Intelligent Nutrient Solution and Drainage Recycling Control System Based on Root-Zone Data Analysis for Smart Greenhouses

Abstract

According to an embodiment of the present invention, an intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse is provided. This system comprises: A drainage collection unit that collects drainage discharged from the greenhouse cultivation area, and A drainage sensor unit for measuring the EC, pH, temperature, water level, etc. of the above drainage, and A drainage recycling control unit that determines whether the drainage is sterilized, concentration, mixing ratio, and safety status based on drainage status data input from the drainage sensor unit, and A drainage treatment unit that drives a sterilizer, a mixing valve, a drainage transfer pump, a drain valve, etc., according to a control signal generated by the above-mentioned control unit to perform sterilization, mixing, and recycling processes of the drainage, and It includes a safety control module that generates an alarm, stops the recycling process, and switches to drainage mode if the drainage status deviates from set safety standards.

Description

Technology Field

[0001] The present invention relates to the field of smart agriculture, and more specifically, to an intelligent nutrient solution and drainage recycling control system based on root zone data analysis for smart greenhouses, which can integrally perform nutrient solution supply and drainage recovery control for crop cultivation in a greenhouse on a single control board. Background Technology

[0003] With the recent advancement of smart farming technology, various automation systems are being developed to precisely control the crop growth environment within greenhouses. Among these, hydroponic cultivation systems have established themselves as a core technology for enhancing productivity by supplying nutrients and water in optimal ratios according to the crop's growth stage. These systems generally consist of nutrient tanks, pumps, valves, sensors, and controllers, and automatically control parameters such as EC (electrical conductivity), pH, and flow rate based on the crop's growth stage and environmental conditions.

[0005] However, conventional hydroponic systems have structures in which the nutrient supply unit and the drainage management unit are independent of each other, making it difficult to efficiently recover or recycle the residual nutrient solution (drainage) supplied to crops. Most existing hydroponic systems simply mix and supply the nutrient solution, and the drainage discharged from the crops is typically discharged through a separate drainage line or manually recovered and reprocessed to be reused as raw water. This approach leads to problems such as waste of nutrient solution, water pollution, increased labor, and energy inefficiency.

[0007] Furthermore, in conventional systems, the control of nutrient solution supply and drainage recycling were performed on separate control boards, which made data inter-system synchronization difficult and resulted in issues such as delays in synchronizing sensor measurements and control interference. For instance, errors could occur, such as the EC or pH conditions set in the nutrient solution supply unit being inconsistent with the timing of drainage measurement, or the pump running idle due to delays in detecting the water level. Consequently, the accuracy of nutrient solution supply was reduced, and problems such as abnormal water levels in the drainage tank, incomplete sterilization, and imbalances in recycling rates frequently occurred.

[0009] Furthermore, because conventional control systems process control signals from each sensor and actuator individually, control complexity increases rapidly in environments with multiple zones or multi-crop cultivation. As the number of sensors increases, input / output ports on the control board become insufficient, leading to inefficiencies that require the installation of additional expansion modules. Additionally, communication delays degrade the reliability of real-time control. In particular, when greenhouses are large or nutrient concentrations and supply amounts vary by zone, existing systems cannot dynamically control these factors and operate using a fixed control method, making precise nutrient management impossible.

[0011] Furthermore, while the operation of sterilizers, mixing valves, and tank level sensors must be synchronized in the wastewater recycling process, conventional technology operates these devices individually based on independent control logic. This results in safety issues, such as the failure to transmit sterilization completion signals, delayed water level detection leading to overflow, or the recirculation of unsterilized wastewater. These problems necessitate improvement, as they can lead not only to reduced agricultural productivity but also to the spread of pathogens and crop damage.

[0013] Therefore, there is a need to develop a system capable of managing nutrient solution supply and drainage recovery in a greenhouse environment in real time from a single integrated control board, and controlling the concentration, temperature, sterilization status, water level, and supply timing of the nutrient solution using an integrated algorithm by synchronizing data from various sensors (EC, pH, flow rate, water level, etc.). Furthermore, there is an urgent need for integrated control technology that can simultaneously ensure safety and efficiency by immediately detecting system abnormalities (e.g., excessive concentration, low water level, sterilizer malfunction, etc.), providing an alarm, and automatically switching to a drainage mode. Prior art literature

[0015] Republic of Korea Published Patent 10-2022-0154498 (2022.11.22) The problem to be solved

[0016] This invention aims to resolve the inaccuracies in monitoring drainage conditions, omission of sterilization treatment, non-uniform concentration, delayed response to abnormal tank levels, and the risk of malfunction in emergency situations inherent in existing systems, during the process of efficiently recovering, sterilizing, and mixing drainage discharged from greenhouses and nutrient solution systems for recycling. Specifically, the purpose is to prevent abnormal drainage from being reintroduced to crops by monitoring the conditions of the drainage, such as EC, pH, temperature, and water level, in real time, and immediately switching to a safety mode or performing drainage treatment if the standards are exceeded.

[0018] Furthermore, the present invention aims to improve the sterilization quality of the drainage, the stability of the mixing ratio control, the attainment of target concentration values, and the recycling efficiency by integrally controlling actuators used in the drainage recycling process, such as drainage sterilizers, mixing valves, and drainage pumps. In particular, by processing the determination of sterilization status, detection of water level abnormalities, zone-specific drainage flow control, and emergency stop logic on an integrated control board, the invention aims to prevent the inflow of contaminants or the spread of pathogens during greenhouse operation and to enhance the overall safety and reliability of the system. means of solving the problem

[0020] To solve the aforementioned problem, according to an embodiment of the present invention, an intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse is provided. This system comprises:

[0021] A drainage collection unit that collects drainage discharged from the greenhouse cultivation area, and

[0022] A drainage sensor unit for measuring the EC, pH, temperature, water level, etc. of the above drainage, and

[0023] A drainage recycling control unit that determines whether the drainage is sterilized, concentration, mixing ratio, and safety status based on drainage status data input from the drainage sensor unit, and

[0024] A drainage treatment unit that drives a sterilizer, a mixing valve, a drainage transfer pump, a drain valve, etc., according to a control signal generated by the above-mentioned control unit to perform sterilization, mixing, and recycling processes of the drainage, and

[0025] It includes a safety control module that generates an alarm, stops the recycling process, and switches to drainage mode if the drainage status deviates from set safety standards.

[0028] In the above-described embodiment, the drainage recycling control unit includes an emergency drainage control logic that analyzes abnormal conditions such as changes in EC and pH from the drainage sensor unit, sudden temperature changes, determination of non-sterilization, and detection of low and high tank water levels, and automatically blocks the drainage recycling process and opens the drainage valve if the abnormal condition persists for longer than a set delay time.

[0030] In addition, in any one of the aforementioned embodiments, the drainage treatment unit detects the operating time, sterilization temperature, and whether sterilization is complete in real time of the sterilizer, and includes a sterilization completion verification logic to prevent drainage that has not been sterilized from flowing into a mixing or recycling process, and if sterilized drainage is detected, an alarm is generated and the unit automatically switches to a drainage mode.

[0032] In addition, in any one of the aforementioned embodiments, the drainage sensor unit includes an EC sensor, a pH sensor, a temperature sensor, a water level sensor, and a WCM-based moisture content sensor, and the control unit performs a zero correction function and a span correction function to maintain the measurement accuracy of the sensors, and includes a self-diagnosis function that determines whether there is a sensor malfunction by diagnosing the difference between the sensor values ​​before and after correction.

[0034] In addition, in any one of the aforementioned embodiments, the system is configured to communicate with a cloud server to collect and learn data such as drainage EC, drainage temperature, sterilizer operation records, changes in mixing ratio, and accumulated drainage volume, and to predict the possibility of drainage contamination, the possibility of sterilization failure, and the risk of excessive or insufficient drainage concentration through machine learning-based analysis, and to proactively generate an alarm or adjust the drainage recycling process according to the prediction results. Effects of the invention

[0036] According to the present invention, the stability and efficiency of wastewater recycling are significantly improved by precisely measuring wastewater generated within a greenhouse based on sensors and automatically performing sterilization, mixing, and recycling processes. In particular, the EC, pH, temperature, and water level of the wastewater are detected in real time to determine the condition of the wastewater, and by automatically controlling the mixing valve, sterilizer, and transfer pump based on the results, nutrient solution of an appropriate concentration can be stably supplied.

[0038] In addition, by including a safety control function that automatically switches to drainage mode and generates an alarm when the drainage sensor value exceeds the set standard or when an incomplete sterilization state is detected, it is possible to prevent the re-supply of abnormal drainage and effectively prevent crop damage and the spread of pathogens.

[0040] Furthermore, by diagnosing potential drainage contamination, risks of sterilization failure, and changes in drainage concentration in advance through cloud-based analysis and prediction algorithms, proactive and predictive safety control is possible. Consequently, this reduces the maintenance burden of greenhouses and significantly improves the level of automation in smart nutrient solution and drainage management. Brief explanation of the drawing

[0042] FIG. 1 is an overall configuration diagram of a nutrient solution and drainage integrated control system for a greenhouse according to one embodiment of the present invention; FIG. 2 is a block diagram showing the configuration of an integrated board (30) according to one embodiment of the present invention in more detail; FIG. 3 is a schematic diagram showing the overall structure of a nutrient solution control system and a drainage recycling system according to an embodiment of the present invention; FIG. 4 is a drawing illustrating the detailed structure of the nutrient solution control system in FIG. 3; FIG. 5 is a schematic diagram illustrating the detailed configuration of the drainage recycling system in FIG. 3; FIG. 6 is a diagram showing the overall flowchart of an irrigation control algorithm according to one embodiment of the present invention; FIG. 7 is a diagram showing an irrigation correction guideline for each growth stage according to an embodiment of the present invention; FIG. 8 is a flowchart showing an automatic correction coefficient update algorithm according to an embodiment of the present invention; FIG. 9 is a diagram showing the overall flowchart of a cloud-based predictive irrigation control system according to an embodiment of the present invention; FIG. 10 is a diagram illustrating the configuration and control flow of a drainage recycling and safety control system according to an embodiment of the present invention, wherein (A) illustrates sterilization control for drainage recycling and (B) illustrates mixing control for drainage recycling; FIG. 11 is an exemplary drawing illustrating a flowchart of a drainage recycling process according to an embodiment of the present invention; FIG. 12 is a diagram exemplarily showing a system main screen according to an embodiment of the present invention; FIG. 13 is a diagram exemplarily showing a monitoring screen of a nutrient solution system according to an embodiment of the present invention; FIG. 14 is a diagram exemplarily showing a main alarm status data screen according to an embodiment of the present invention; FIG. 15 is a diagram exemplarily showing a drainage alarm monitoring screen according to an embodiment of the present invention; FIG. 16 is a diagram exemplarily showing a backwash and drainage control setting screen according to an embodiment of the present invention; FIG. 17 is a diagram exemplarily illustrating a system view monitoring screen including a set value, remaining amount, accumulated value, etc., according to an embodiment of the present invention; FIG. 18 is a diagram exemplarily showing a screen for setting whether to calibrate a nutrient solution dispenser sensor and whether to use an alarm according to an embodiment of the present invention; FIG. 19 is a diagram exemplarily showing a screen for setting whether a nutrient solution device is used and an alarm deviation according to an embodiment of the present invention; FIG. 20 is a drawing exemplarily showing a drainage recycling main screen according to an embodiment of the present invention; FIG. 21 is a diagram exemplarily showing a drainage recycling mixing valve control setting screen according to an embodiment of the present invention; FIG. 22 is a diagram exemplarily showing a setting screen for a drainage recycling sterilizer according to an embodiment of the present invention; FIG. 23 is a diagram exemplarily showing a view screen of real-time sensor data (drainage / sterilizer) for drainage recycling according to an embodiment of the present invention; FIG. 24 is a diagram exemplarily showing a screen for setting whether to use drainage and sterilizer sensor calibration and alarm according to an embodiment of the present invention; FIG. 25 is a diagram exemplarily showing an alarm deviation setting screen of a drainage and sterilization device according to an embodiment of the present invention; FIG. 26 is a diagram exemplarily showing a system main function usage page setting screen according to an embodiment of the present invention; and FIG. 27 is a diagram illustrating an exemplary system startup check (manual output control test) screen according to one embodiment of the present invention. Specific details for implementing the invention

[0043] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms.

[0045] The embodiments described herein are provided to ensure that the disclosure of the invention is complete and to fully inform those skilled in the art of the scope of the invention. The invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques are not specifically described to avoid the invention being interpreted ambiguously.

[0047] Throughout the specification, the same reference numerals refer to the same components. Furthermore, the terms used (mentioned) in this specification are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. Additionally, components and operations referred to as "comprising (or comprising)" do not exclude the presence or addition of one or more other components and operations.

[0049] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless otherwise defined.

[0051] Embodiments of the present invention will be described below with reference to the attached drawings.

[0052] Referring to FIG. 1, the intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse according to the present invention is composed of a web-based integrated control platform (1), a GCS server (2), an environment control system (3), a UI integrated control terminal (10), a TCP / 232 converter (20), an integrated board (30), and a nutrient solution processing board (31) and a drainage recycling processing board (32) inside the same.

[0054] A web-based integrated control platform (1) is a remote control server or web application operating in a cloud environment, and communicates with a GCS server (2) installed in a greenhouse to monitor data such as the overall operating status, sensor values, alarm history, and watering logs of the nutrient solution system (4) in real time, and transmits user control commands to a subordinate device through the GCS server (2).

[0056] Users can check the nutrient solution and drainage control status or change control settings from a remote location by accessing the platform via a PC or mobile device. More specifically, the web-based integrated control platform (1) stores sensor data such as EC, pH, water level, flow rate, and temperature, which are periodically collected from the nutrient solution system (4), in a database within the server, and the stored data is visualized in the form of a dashboard and provided to the administrator.

[0058] Additionally, the platform (1) can generate an alarm notification when a specific threshold is exceeded and can remotely execute an automatic watering program or a drainage recycling mode according to a set schedule.

[0060] The GCS server (2) is a central gateway device of the present invention and performs the role of relaying data communication between the upper web-based integrated control platform (1) and the lower environment control system (3) and nutrient control system (4).

[0062] The GCS server (2) performs real-time data transmission based on the TCP / IP protocol and collects data related to the nutrient solution (EC, pH, flow rate, water level, drainage status, etc.) as well as environmental information such as temperature, humidity, CO₂ concentration, and solar radiation provided by the environmental control system (3), and stores it in a database. This integrated data can be utilized in the automation and predictive control algorithms for nutrient solution control.

[0064] More specifically, the GCS server (2) transmits data collected from each control board (31, 32) in the form of RS232 or TCP packets to the upper platform (1) via the MQTT or REST API protocol. Additionally, the server (2) performs the function of automatically generating a signal to start watering by analyzing the rate of change in solar radiation and internal temperature received from the environmental control system (3), or transmitting an automatic dilution command to the integrated board (30) if the nutrient solution concentration is higher than the standard.

[0066] The environmental control system (3) is a system that measures and controls environmental conditions inside the greenhouse, and commercial greenhouse control equipment such as Magma Plus can be used. This system measures the temperature, humidity, solar radiation, ventilation window opening / closing rate, CO₂ concentration, etc. of the greenhouse and transmits the data to the GCS server (2) and the UI integrated control terminal (10). By doing so, the amount of nutrient solution supplied, the drainage recovery rate, and the irrigation cycle are adjusted according to environmental conditions, thereby enabling the optimal supply of nutrient solution suitable for the growth stage of the crop.

[0068] More specifically, the environmental control system (3) simultaneously detects the weather conditions outside and inside the greenhouse, calculates the evapotranspiration (ET) based on data such as the amount of solar radiation accumulated over time, the temperature difference between the inside and outside, and the rate of change in wind speed, and transmits the value to the GCS server (2) to provide it as an input variable for the automatic irrigation start condition. In this way, precise nutrient solution control based on the actual evaporation of the crop, rather than simple timer control, is possible.

[0070] More specifically, the environmental control system (3) is an integrated environmental control system for comprehensively managing the greenhouse environment, and measures the weather outside the greenhouse (solar radiation, outside temperature, wind direction, wind speed, rainfall, etc.) and the weather inside the greenhouse (internal temperature, humidity, CO₂ concentration, etc.) in real time. In addition, it is configured to precisely control the temperature, humidity, CO₂, and light environment of the greenhouse space by including other energy and environmental monitoring sensors.

[0072] In the environment control system (3), target values ​​(environmental guidelines) for the optimal temperature, humidity, light, and CO₂ environment required for crop cultivation can be set in advance. Based on this, the user specifies the operating conditions of drive devices such as ventilation windows, shading curtains, circulation fans, and heaters, and the system automatically controls each drive device by analyzing real-time weather data inside and outside the greenhouse.

[0074] For example, it operates by automatically closing shading curtains when solar radiation is high, or by opening ventilation windows and fans when the internal temperature rises. Through this, the interior of the greenhouse is automatically established and maintained at a standard environment set by the user, ensuring a stable crop growth environment even in the event of sudden weather changes.

[0076] In addition, the environmental control system (3) does not merely control the physical environment, but also performs the function of predicting and evaluating the growth response of crops to changes in the greenhouse environment. That is, the growth amount of crops (e.g., amount of photosynthesis, amount of transpiration, rate of increase in biomass, etc.) can be estimated according to the environmental conditions created by the controller, and the results are transmitted to the GCS server (2) or an external analysis module to analyze whether the greenhouse environment has been effective on the crops and what control parameters require supplementation or correction. The results of this analysis are fed back to the environmental control system (3) and are reflected in the control of actuators such as ventilation, lighting, heating, and irrigation in the next control cycle.

[0078] Accordingly, the environment control system (3) included in the integrated nutrient solution and drainage control system (4) for a greenhouse of the present invention goes beyond a simple greenhouse environment monitoring function and performs the role of optimizing the timing of nutrient solution supply, the amount of supply, and the drainage recycling rate in real time by comprehensively analyzing external weather conditions and internal growth environment. That is, the environment control system (3) functions as a source of input data for the intelligent nutrient solution control algorithm of the present invention and as a core component forming a feedback control loop based on crop growth response.

[0080] The UI integrated control terminal (10) is an interface device installed at the greenhouse site that allows a user to directly operate the system or monitor its status. This terminal includes a touchscreen-based user interface and displays the operating status, sensor values, alarm history, etc., of the nutrient solution processing board (31) and the drainage solution recycling processing board (32) in real time.

[0082] In addition, the UI integrated control terminal (10) is capable of bidirectional communication with the GCS server (2) and the environment control system (3), and performs a synchronization function so that remote commands and field control commands do not conflict.

[0084] More specifically, the UI terminal (10) polls the status of each control board at 1-second intervals, and the received data is stored in a local DB so that recent driving history can be viewed even in an offline state. In addition, user commands can be filtered according to a priority table so that local control commands are executed first in the event of a conflict with a higher-level GCS server command.

[0086] The TCP / 232 converter (20) is a device that converts the communication protocol between the UI integrated control terminal (10) and the integrated board (30). Generally, the UI terminal uses TCP / IP-based Ethernet communication, and the integrated board uses RS-232 or RS-485-based serial communication; the converter performs conversion between these two communication standards to ensure data compatibility. That is, control commands and sensor signals are mutually converted to enable real-time control.

[0088] More specifically, the TCP / 232 converter (20) incorporates buffering and error recovery algorithms to minimize transmission delay of command data and performs retransmission through CRC verification in the event of data packet loss. Additionally, it can be designed with a multi-port structure to simultaneously branch and transmit signals to multiple control boards (31, 32).

[0090] The integrated board (30) is a core component of the present invention and is configured by integrating a nutrient solution processing board (31) and a drainage recycling processing board (32) into a single hardware frame. This integrated board manages all input / output (I / O) signals required for nutrient solution supply and drainage recycling control, and performs integrated functions such as sensor data collection, control of pumps and valves, operation of sterilization devices, and safety interlocks. In addition, each board includes an independent microcontroller (MCU) to enable parallel control, and mutual data exchange is performed through the same communication protocol.

[0092] More specifically, the integrated board (30) performs real-time data synchronization by configuring a common communication bus between each board, and automatically corrects the recycling concentration ratio by referencing EC and pH data measured by the nutrient solution treatment board (31) in the drainage water recycling treatment board (32). In addition, it incorporates a power supply unit, a relay module, and a protection circuit to perform an automatic shut-off function in the event of abnormal current, short circuit, or sensor error in each driver.

[0094] The nutrient solution treatment board (31) controls actuators such as a raw water pump, a nutrient solution pump, a solenoid valve, and a heating device, and collects data measured from an EC sensor, a pH sensor, a flow rate sensor, a low water level sensor, etc. to control the concentration and temperature of the nutrient solution supplied to the crop. The board can adjust the irrigation cycle and nutrient solution concentration in real time by reflecting the greenhouse internal temperature and solar radiation information received from the environment control system (3).

[0096] More specifically, the nutrient solution treatment board (31) compares the deviation between the set target EC value and the actual value to adjust the pump driving time using a PID control method and automatically corrects the supply amount using flow sensor data. In addition, if the amount of solar radiation inside the greenhouse decreases rapidly, it can perform a correction algorithm to automatically reduce the amount of watering.

[0098] The drainage recycling treatment board (32) recovers the drainage discharged from the crop and processes it into a recyclable nutrient solution by controlling a sterilizer and a mixing valve. This board determines whether a sterilization process is necessary based on the measurements of the EC / pH sensor and the water level sensor, and controls the discharge solenoid valve to open and discharge contaminated water if the standard conditions are not met. Additionally, after sterilization is completed, the drainage is mixed with raw water at a certain ratio and re-supplied to the nutrient solution treatment board (31), thereby minimizing wastewater generation.

[0100] More specifically, the drainage recycling processing board (32) simultaneously checks the sterilizer operation completion signal and the level of the water level sensor to prevent recirculation when sterilization is not completed. In addition, if a condition such as a power failure, overheating, or a decrease in flow rate is detected, it automatically switches to a drainage mode, and this condition information is displayed as an alarm on the UI integrated control terminal (10).

[0102] The nutrient solution and drainage integrated control system (4) for a greenhouse according to the present invention automatically controls the supply of nutrient solution and the recycling of drainage solution according to the environmental conditions of the greenhouse through organic linkage between each of the above components.

[0104] Control parameters set via the UI integrated control terminal (10) or web-based platform (1) are transmitted to the integrated board (30) via the GCS server (2), and each control board controls actuators such as pumps, valves, and sterilizers in real time by reflecting sensor feedback values. Through this, smart control is possible to maximize nutrient solution supply efficiency and prevent drainage contamination and resource waste.

[0106] More specifically, the system calculates the time to start automatic irrigation by comprehensively analyzing solar radiation, transpiration, internal humidity, etc., and dynamically corrects the nutrient solution concentration by calculating the drainage water recycling rate in real time. In addition, all operation data is transmitted to the cloud via the GCS server (2) and can be used for long-term growth analysis and irrigation pattern optimization.

[0108] FIG. 2 is a block diagram showing the configuration of an integrated board (30) according to one embodiment of the present invention in more detail.

[0110] Referring to FIG. 2, the integrated board (30) is configured to be divided into a nutrient solution processing board (31) and a drainage solution recycling processing board (32). Each board (31, 32) receives an analog signal (V, mA), a pulse signal (CNT), or an On / Off signal from various external sensors, performs calculation and control logic in an internal processing unit (312, 322), and then transmits a control signal to an actuator such as a pump, valve, sterilizer, or heater through an output unit (313, 323).

[0112] The nutrient solution processing board (31) consists of a nutrient solution sensor input section (311), a nutrient solution processing section (312), and a nutrient solution output section (313).

[0113] The nutrient solution sensor input unit (311) receives signals from various sensors required for nutrient solution control in the greenhouse. The main sensors that are input are as follows.

[0114] - EC Sensors (EC1, EC2): Detect the EC (electrical conductivity) of the nutrient solution in real time and utilize it to control nutrient concentration.

[0115] - pH Sensor (pH1, pH2): Measures the acidity (pH) of the nutrient solution to control the opening and closing of the acid / alkali control valve.

[0116] - Flow Sensor: Measures the pump discharge flow rate using a pulse counter (CNT) method and corrects the actual supply amount against the set amount.

[0117] - Solar Radiation Sensor: Detects solar radiation in units of W / m² and utilizes it as environmental correction data to regulate irrigation volume and cycle.

[0118] - Air temperature and humidity sensor: An NTC 13kΩ-based temperature and humidity sensing sensor used for calculating transpiration (ET).

[0119] - Water Content Measurement (WCM): An RS-485 communication-based soil moisture sensor used to determine the irrigation start time.

[0120] - Pipe pressure gauge: Measures pressure values ​​in a total of 6 sections, including the upstream and downstream ends of the filter, the dosing section inlet, and the raw water mixing section, to diagnose pump malfunctions or blockages.

[0121] - Pipe thermometer: Measures the temperature at the downstream end of the raw water pump, downstream end of the nutrient solution pump, supply pipe, etc., to stabilize the temperature of the mixed water.

[0122] - Low Water Level Sensor: Detects low water levels in each tank, such as raw water, liquid fertilizer, and drainage, to prevent pump idling and trigger a water supply alarm.

[0124] All of these sensor signals are digitized through an ADC (Analog to Digital Converter) and transmitted to a nutrient solution processing unit (312).

[0126] The nutrient solution processing unit (312) calculates the nutrient solution mixing ratio, supply sequence, and the operating time of the pump and solenoid valve based on data received from the sensor input unit (311). For example, if the EC sensor value is lower than the reference, the liquid fertilizer dosing channel is opened, and if the pH is higher than the reference, the acid control valve is opened to correct the concentration. In addition, crop transpiration is calculated using solar radiation and temperature and humidity data, and this is used as a condition for determining the start of irrigation.

[0128] The nutrient solution output unit (313) transmits a 24V AC relay control signal to each driver based on the result calculated by the control unit (312). Representative output items are as follows.

[0129] - Raw water pump, nutrient solution pump

[0130] - Liquid fertilizer solenoid valves A1~C2 (for fertilizer and acid / alkali control)

[0131] - Electronic valves for each zone (Zones 1~8)

[0132] - Drainage solenoid valve

[0133] - Raw water tank heating device

[0134] - Alarm output section

[0136] The nutrient solution output unit (313) includes an overcurrent protection circuit for all output channels, and each signal is monitored in real time at the UI integrated control terminal (10).

[0138] The drainage recycling processing board (32) consists of a drainage sensor input section (321), a drainage processing section (322), and a drainage output section (323).

[0139] The drainage sensor input unit (321) receives sensor signals necessary for drainage recovery and recycling control. The main sensors input are as follows.

[0140] - Drainage EC sensor (EC3) and drainage pH sensor (pH3): Measures the concentration and acidity of the discharged drainage to determine whether it is recyclable.

[0141] - Drainage Recycling EC4, pH4 Sensor: Monitors water quality after the sterilization and remixing process to determine whether resupply conditions are met.

[0142] - Water level sensor (low / high): Detects the water level of each tank before and after treatment to control the operation of the sterilizer and the timing of valve opening and closing.

[0143] - Sterilizer Status Sensor: Monitors the start and stop status of the sterilizer and automatically switches to drainage mode in case of an abnormality.

[0145] These sensor inputs are transmitted to the drainage processing unit (322) in the form of analog or digital signals.

[0147] The drainage processing unit (322) analyzes the collected drainage data and selects an appropriate mode among sterilization, recycling, and drainage. For example, when a sterilization completion signal is confirmed and the EC·pH value is within the standard range, the mixing valve is opened to perform resupply, and when it deviates from the standard, the drainage solenoid valve is opened. In addition, if the water level of the tank before processing drops below a certain level or the sterilizer temperature is insufficient, an automatic stop signal is generated.

[0149] The drainage output unit (323) outputs a control signal generated in the drainage processing unit (322) in the form of relay control, and the main output items are as follows.

[0150] - Drainage sterilization and recycling zone electronic valves (1~8)

[0151] - Mixing valve open / close signal

[0152] - Sterilizer start control

[0153] - Alarm output and safety interlock circuit

[0155] All output signals are driven based on 24V AC, and when a driver malfunction occurs, an overcurrent cutoff and status feedback signal is displayed on the UI integrated control terminal (10).

[0157] The nutrient solution treatment board (31) and the drainage recycling treatment board (32) share the same communication bus line to exchange data in real time. For example, the target EC value calculated by the nutrient solution treatment unit (312) is input into the recycling concentration correction logic of the drainage treatment unit (322), and conversely, the actual drainage EC value measured by the drainage treatment unit (322) is fed back to the mixing ratio control of the nutrient solution treatment unit (312). Through this mutual reference structure, the nutrient solution supply and drainage recycling operate synchronously, and it is possible to minimize nutrient loss and reduce wastewater in the entire system.

[0159] In addition, the integrated board (30) ensures hardware stability by integrating the power circuit, protection circuit, and communication circuit of each board, and the input / output status of all signals can be remotely monitored from the UI integrated control terminal (10) or the GCS server (2).

[0161] The integrated board (30) shown in FIG. 2 can simultaneously realize real-time automation, data linkage, and safety control of nutrient supply and drainage recycling in a greenhouse by integrally processing various sensor inputs and relay drive outputs required for nutrient and drainage control in a single hardware frame.

[0163] FIG. 3 is a schematic diagram showing the overall structure of a nutrient solution control system and a drainage recycling system according to an embodiment of the present invention, FIG. 4 is a detailed structure of the nutrient solution control system in FIG. 3, and FIG. 5 is a schematic diagram showing the detailed configuration of the drainage recycling system in FIG. 3.

[0165] As illustrated in FIGS. 3 to 5, the nutrient solution system consists of a raw water tank, a raw water motor, a mixing tank, a nutrient solution motor, dosing channels (A1, B1, A2, B2, C, D), a supply flow meter, a filter, and a greenhouse supply line. EC sensors (EC1, EC2), pH sensors (pH1, pH2), pressure gauges, temperature sensors, etc. are installed in each section to monitor the quality and flow rate of the nutrient solution in real time.

[0167] According to this configuration, it includes a raw water supply stage; a nutrient solution mixing stage; a circulation and supply stage; and a feedback control stage.

[0168] During the raw water supply stage, the raw water motor starts when the low water level gauge of the raw water tank is above a certain level, and the raw water is transferred to the mixing tank when the pressure sensor and temperature sensor downstream of the raw water pump are within the normal range. The raw water temperature is pre-controlled through the raw water tank heater, which is a measure to enhance the stability of nutrient solution mixing.

[0170] In the nutrient solution mixing stage, liquid fertilizer is injected into the mixing tank through a plurality of dosing channels (A1~D) connected to the raw water line. Each channel is controlled by a solenoid valve (liquid fertilizer solenoid valve A1~C2), and the injection ratio is automatically adjusted according to the EC and pH target values ​​calculated by the nutrient solution treatment board (31). EC sensor 1 and pH sensor 1 monitor the concentration inside the tank and repeat dosing until the reference concentration is reached.

[0172] In the circulation and supply phase, after mixing is complete, the nutrient solution motor is activated, and the nutrient solution is transferred to the greenhouse supply pipe via the supply flow meter. The supply flow meter monitors the flow rate in real-time via pulse signals and automatically shuts off the valve when the set supply amount is reached. Additionally, the supply pipe is equipped with pressure sensors before and after the filter to detect filter clogging, and switches to an automatic cleaning mode if the differential pressure exceeds a threshold. After filtration, the nutrient solution is distributed to each cultivation zone through zone-specific electronic valves (Zones 1–8) and supplied to the crops.

[0174] In the feedback control stage, a portion of the drainage discharged after greenhouse supply is recovered through the greenhouse drainage collection well and flows into the drainage tank (before treatment). At this time, the pipe temperature sensor, the pressure gauge at the downstream end of the filter, and the drainage EC / pH sensor 3 measure data and utilize it to calculate the irrigation efficiency and concentration correction values ​​of the system. The measured values ​​are transmitted to the UI integrated control terminal (10) and the GCS server (2) and reflected in the correction algorithm for the next irrigation cycle.

[0176] Referring to Fig. 5, the configuration and operation of the drainage recycling system will be described.

[0177] The drainage recycling system consists of a drainage tank (before treatment), a sterilizer, a drainage tank (after treatment), a drainage recycling device, a mixing valve, and a drain valve. Each tank is equipped with EC / pH sensors (EC3, pH3, EC4, pH4) and water level sensors (high and low levels) to monitor the drainage treatment status in real time.

[0179] The drainage recycling operation may largely include a drainage recovery step; a sterilization and reprocessing step; a drainage mixing and resupply step; and safety and alarm control.

[0180] In the drainage recovery stage, the drainage discharged from the crops in the greenhouse is recovered into the drainage tank (before treatment) along the drainage line. When the high-level gauge of the drainage tank exceeds the set value, a signal is transmitted to the UI terminal (10) to switch to the sterilization preparation stage. At this time, the EC3 and pH3 values ​​of the drainage are measured to determine whether it is recyclable.

[0182] In the sterilization and reprocessing stage, the drainage processing board (32) outputs a sterilizer start signal to process the drainage using high-temperature circulation or ultraviolet (UV) sterilization. During the operation of the sterilizer, the low water level sensor of the pre-processing tank and the sterilizer temperature sensor are linked to each other so that the system stops immediately in case of insufficient drainage or overheating. After sterilization is completed, the drainage is transferred to the post-processing drainage tank, at which time the EC4 and pH4 sensors re-measure the quality after sterilization. If it is within the set standard range, it automatically switches to "recycling mode," and if it deviates from the standard, it automatically switches to "drainage mode."

[0184] In the drainage mixing and resupply stage, the drainage determined to be recyclable is mixed with raw water through a 3-way valve installed in the raw water line. The mixing ratio is controlled based on the drainage EC value, and the optimal mixing ratio is calculated in real time through communication between the nutrient solution treatment board (31) and the drainage solution treatment board (32). The mixed solution is supplied back to the mixing tank through the raw water motor and recycled as new nutrient solution. Conversely, when it is determined not to be recyclable, the drain valve is opened and discharged to the outside.

[0186] When an abnormal condition such as a sterilizer malfunction, a sensor short circuit, or a water level discrepancy is detected during the safety and alarm control phase, the drainage processing board (32) immediately opens the drainage valve and cuts off the power to the sterilizer. At the same time, an alarm signal is displayed on the UI integrated control terminal (10), and a log is transmitted to the GCS server (2). Through this dual safety structure, the re-supply of contaminated drainage or the supply of an overconcentrated amount is prevented.

[0188] As can be seen in the overall structure of FIG. 3, the present invention comprises a nutrient solution supply system and a drainage recycling system as a single integrated circulation control loop (Closed Loop). That is, when a portion of the nutrient solution supplied to the greenhouse is absorbed by the crop and the remainder is recovered as drainage, sensor data (EC, pH, temperature, flow rate, water level, etc.) of this drainage is directly transmitted to the drainage recycling processing board (32), and the recycling determination result calculated by the processing board (e.g., recyclable / unrecyclable, mixing ratio, etc.) is transmitted back to the nutrient solution processing board (31) to automatically correct the nutrient solution mixing ratio and supply amount.

[0190] In this way, the cyclical process of nutrient solution supply -> drainage recovery -> sterilization -> mixing -> resupply is implemented as a single closed loop, thereby forming an autonomous feedback structure in which the entire system monitors its status in real time and self-corrects.

[0192] Regarding the control linkage of the nutrient solution supply stage, the nutrient solution processing board (31) dynamically updates the target EC value and pH setting value of the nutrient solution based on real-time data transmitted from the GCS server (2) and the environmental control system (3). For example, when solar radiation, internal temperature, humidity, CO₂ concentration, etc. are input from the environmental control system (3), the crop's transpiration (ET, Evapotranspiration) and estimated water consumption are calculated through this data, and the irrigation start time and supply amount are automatically determined according to the results.

[0194] When an irrigation start command is issued, the raw water pump and the nutrient solution pump are driven sequentially, and liquid fertilizer is injected into the mixing tank through the dosing channels (A1~D). During this process, real-time measurements from the EC / pH sensors (1,2) are transmitted to the control board, and if there is an error with the target concentration, the injection ratio is immediately adjusted.

[0196] When the drainage is determined to be recyclable, the sterilizer is activated to remove bacteria, mold, and pathogens using high-temperature circulation or ultraviolet (UV) light. During sterilization, the low water level sensor of the pre-treatment drainage tank, the sterilizer temperature sensor, and the pressure sensor are monitored in real time, and if the level exceeds the stable range, the sterilizer is stopped immediately. After sterilization is completed, the drainage is transferred to the post-treatment tank, at which time the EC / pH sensor (4) re-measures to check if the quality after sterilization is within the standard range. If it is within the standard range, it is automatically diverted to the recycling mixing mode, and if it exceeds the standard range, it is diverted to the drainage mode.

[0199] When the sterilized drainage is deemed recyclable, it joins the raw water line through the drainage recycling mixing valve (3-way valve). At this point, the EC value of the drainage, the EC value of the raw water, and the target EC value of the mixing tank are compared and calculated to automatically determine the mixing ratio. The mixing ratio is calculated using a real-time formula.

[0201] When controlling the mixing of the nutrient solution, the control unit compares the EC value of the raw water (EC_raw) and the EC value of the drained water (EC_drain) and automatically calculates the mixing ratio (α, β) of the raw water and the drained water so that the target EC value (EC_target) can be reached.

[0203] For example, the target EC value can be calculated according to the following relationship.

[0204] EC_target = (EC_raw×α) + (EC_drain×β), where α + β = 1 [Equation 1]

[0205] Here, EC_raw represents the purity of the raw water, EC_drain represents the residual concentration of the drainage, α and β are control parameters for adjusting the mixing ratio, and EC_target represents the target concentration tailored to the crop.

[0207] The control unit automatically adjusts the ratio of α and β based on the relationship shown in the above equation so that the concentration of the nutrient solution after mixing is maintained within the target range (e.g., 1.8 to 2.2 dS / m). The calculated mixing ratio is applied to the control of the opening rate of the drainage recycling mixing valve, and the result is transmitted to the nutrient solution treatment board (31) and used to finely correct or reduce the dosing amount in the next watering cycle.

[0209] The integrated board (30) periodically transmits all sensor data collected from the nutrient solution treatment board (31) and the drainage treatment board (32) to the GCS server (2). The GCS server (2) stores data such as EC, pH, temperature, flow rate, water level, solar radiation, and wind speed in a cloud-based database, and calculates KPIs (performance indicators) such as irrigation efficiency, fertilizer usage efficiency, and recycling rate through an analysis algorithm.

[0211] In addition, the server integrates and analyzes external data (temperature, humidity, wind speed, etc.) transmitted from the environmental control system (3) and feeds back real-time control parameters to each control board so that the watering pattern can be automatically adjusted even in the event of sudden weather changes. For example, if solar radiation increases rapidly, the server issues a correction command such as "increase transpiration -> start watering early -> temporarily increase drainage recycling rate" to prevent water shortage while minimizing fertilizer loss. Conversely, if solar radiation decreases rapidly or at night, "delay watering -> decrease drainage mixing ratio" is applied to suppress unnecessary watering.

[0213] In this way, the nutrient solution and drainage integrated control system of the present invention maximizes resource circulation efficiency within the greenhouse by integrating all steps of ① nutrient solution supply, ② drainage recovery, ③ sterilization treatment, ④ remixing, and ⑤ resupply into a single closed-loop control. In particular, through real-time feedback control based on EC and pH, nutrient loss can be minimized, raw water and fertilizer usage can be reduced, and discharged contaminated water can be minimized. In addition, by integrating with data from the environmental control system (3), irrigation and nutrient solution supply optimized for crop growth are automatically maintained even with changes in weather conditions.

[0215] FIG. 6 shows an overall flowchart of an irrigation control algorithm according to one embodiment of the present invention. The algorithm is composed of a series of processes that automatically perform irrigation start time, irrigation amount, and supply control by comprehensively considering the crop's transpiration rate, moisture content, light intensity, shading rate, and growth stage based on integrated data between an environment control system (3), a GCS server (2), and a nutrient solution control system (4).

[0217] Step S610 is an environmental data collection step. The control unit collects weather data inside and outside the greenhouse through the environmental control system (3). The collected data includes the outside temperature, inside temperature, relative humidity, CO₂ concentration, wind speed, solar radiation, curtain opening rate (shading rate), etc. In addition, by linking with the UI integrated control terminal (10), information such as the moisture content of the substrate, moisture loss amount, and cumulative light accumulation (J / cm²) is obtained from the moisture content sensor, substrate weight scale, pyranometer, WCM sensor, etc. The data collected in this step is subsequently used for calculating transpiration, determining the start of irrigation, correcting nutrient solution concentration, etc.

[0219] Step S620 is the transpiration and moisture content analysis step. The control unit calculates the transpiration rate (ET) per hour according to a crop-specific transpiration model (ET model) using solar radiation and temperature data collected from the environmental control system (3). In addition, it calculates the actual amount of water absorbed by the crop (absorption amount) and the decrease in moisture content of the growing medium by comparing and analyzing the weight loss measured by the growing medium scale with the moisture content sensor value. Through this, the actual water requirement of the crop is predicted in real time, and, for example, the condition for starting irrigation can be set to be satisfied whenever the transpiration rate increases by 100cc. When the temperature rises or light intensity increases, the irrigation cycle is shortened as the transpiration rate increases, enabling precise irrigation control in response to weather changes.

[0221] Step S630 is the irrigation initiation determination step. In this step, the control unit determines whether to start irrigation based on transpiration and moisture content data. Irrigation is initiated when one or more of the following conditions are met.

[0222] (a) Cumulative evaporation ≥ Reference value (e.g., 100cc)

[0223] (b) Decrease in moisture content ≥ Set deviation (e.g., 5%)

[0225] In addition, the start time is adjusted by reflecting changes in the greenhouse's shading rate and light intensity. For example, if the curtain is completely closed with 40% shading, the actual incoming solar radiation is reduced to 60%, so the irrigation start signal is automatically delayed. Conversely, if the light intensity is high or the curtain opening is large, the transpiration rate increases, so irrigation is initiated early. Through such judgments, precise control of irrigation start is realized by considering the crop's water demand, light environment, and temperature changes in real time.

[0227] Next, step S640 is the irrigation amount calculation step. When the start of irrigation is determined, the control unit calculates the irrigation amount for one cycle. The irrigation amount can be calculated as follows.

[0229] Water per irrigation = Evaporation × (1 + Set drainage rate %)

[0231] In other words, by adding a certain ratio (drainage rate) to the crop's water consumption to secure an excess supply during irrigation, the accumulation of salts in the growing medium is prevented and EC balance is maintained. Additionally, precise irrigation amount correction is performed for each zone using correction indicators such as supply amount per unit area (ml / m²), supply amount relative to light intensity (ml / J / cm²), and supply amount per volume of the growing medium. For example, in the case of Solanaceae crops, it is set to supply 1.5 to 2.0 ml / m² of nutrient solution when receiving 1 J / cm² of light, and this value is automatically corrected according to real-time solar radiation and dripper density. Furthermore, the control unit determines the EC target concentration (EC_target) according to the following equation.

[0233] EC target = ( EC raw ×α) + (EC drain ×β)

[0235] Step S650 is the supply control stage. Based on the calculated irrigation volume, the control unit drives the nutrient solution pump, raw water pump, solenoid valve, electronic valve, etc., to supply the actual nutrient solution. During supply, the measurements from the EC sensor and pH sensor are continuously monitored, and if they deviate from the set target values, the dosing amount of the fertilizer channel is automatically corrected. Additionally, if changes in the drainage level or pipe pressure are detected during supply, it determines whether there is an abnormal flow rate or supply imbalance, and immediately triggers an alarm or stops the supply.

[0237] Here, EC_raw is the concentration of the fresh nutrient solution, EC_drain is the concentration of the recovered drainage solution, and α and β are automatically adjusted according to environmental conditions and growth stage. Through this, the concentration of the nutrient solution after mixing is corrected so that it is maintained within the target value (e.g., 1.8~2.2 dS / m), and the result is transmitted to the nutrient solution control board (31) and reflected in the dosing amount adjustment during the next watering cycle.

[0239] S660 is the watering termination and data feedback stage. When watering is terminated, the control unit records data such as total supply amount, drainage amount, drainage rate, moisture content recovery amount, and accumulated solar radiation, and transmits it to the GCS server (2).

[0241] The server analyzes accumulated data to evaluate irrigation efficiency and drainage rates, and provides a "over-irrigation" alert to the user if thresholds are exceeded. Furthermore, based on daily accumulated data, it automatically adjusts the target irrigation volume, start time, and drainage rate for the next irrigation cycle, forming a continuous self-learning control loop throughout the entire system.

[0243] FIG. 7 is a diagram showing an irrigation correction guideline for each growth stage according to an embodiment of the present invention. This diagram represents reference data for dynamically correcting target values ​​of irrigation amount, drainage rate, and nutrient solution concentration (EC) by comprehensively considering the crop growth stage, seasonal weather conditions, and changes in light intensity. That is, it is used as a standard for setting a correction coefficient (α) and target EC and drainage rate to correct the result value of the irrigation control algorithm described in FIG. 6.

[0245] As described, the left column of the table is divided into a total of 6 growth stages based on the crop growth cycle.

[0246] Early stage 1 (September–October): This is the stage immediately after planting, a time when the temperature is high and the leaf area is small, causing the transpiration rate to increase rapidly.

[0247] Early 2 (October–November): This is a period when leaf area expands and the temperature drops slightly, but the amount of light is sufficient.

[0248] Mid-term 1 (November–December): Temperatures drop and light intensity decreases, but crop growth is vigorous, requiring stable irrigation.

[0249] Mid-term 2 (December–February): This is the winter low-light period, a time when both light intensity and temperature are low, minimizing watering.

[0250] Late Period 1 (February–April): This is the period when transpiration becomes active again due to rising temperatures and increased light intensity.

[0251] Late Stage 2 (April–June): This is the late growth stage where high temperatures and strong light conditions are maintained, and the water volume and drainage rate are set to their maximum.

[0253] The average temperature (°C) and average solar radiation (MJ / m²) corresponding to each growth stage are listed. This data is a reference value to be used as a standard value for watering correction calculations, utilizing real-time temperature, humidity, and solar radiation information obtained from the environmental control system (3). For example, in the mid-stage 2, the average solar radiation is low at 6 MJ, so the watering start cycle is extended, and the correction factor is also adjusted to 0.95 to prevent excessive watering. On the other hand, in the late stage 2, the average solar radiation increases to 13 MJ, so the correction factor is raised to 1.2, and the supply amount per unit area is automatically increased.

[0255] The correction factor is a weight that is multiplied by the basic watering amount or target EC value calculated by the watering control algorithm, and it serves to fine-tune the watering amount according to the weather conditions and growth stage. For example, in the 'Initial 1' stage, a correction factor of 0.8 is applied to adjust the watering amount to 80% of the standard value, and in the 'Later 2' stage, 1.2 is applied to increase the watering amount by 20%. These factors are stored in the database of the GCS server (2) and are automatically updated according to the season, light intensity, and growth stage.

[0257] In the right column of the table, the target EC (dS / m) and drainage rate (%) for each stage are set. These are reference values ​​to prevent the accumulation of fertilizer concentration and salts in the nutrient solution, and the nutrient solution treatment board (31) and the drainage recycling treatment board (32) are automatically controlled based on these.

[0259] For example, in the initial stage 1, the target EC is set to 1.8 dS / m and the drainage rate to 15% to supply low-concentration nutrient solution while preventing excessive discharge, and in the later stage 2, the target EC is increased to 2.2 dS / m and the drainage rate to 25% to prevent fertilizer concentration loss in high temperature and high light environments and to suppress salt accumulation. These target values ​​are automatically corrected by comparing them with actual drainage EC and pH measurements in the feedback stage (S660) after irrigation is finished, and are reflected as the set values ​​for the next irrigation cycle.

[0261] The guideline of Fig. 7 is not merely a simple setting table, but is reflected in dynamic control by interpolating the correction factor (α), target EC, and drainage rate in real time based on real-time temperature and light intensity data provided by the environmental control system (3). That is, it is smoothly corrected even in the boundary sections between seasons and growth stages, so stable irrigation control is possible even with changes in crop transpiration or sudden environmental changes.

[0263] Accordingly, the irrigation correction guideline for each growth stage illustrated in FIG. 7 of the present invention enables precise irrigation control considering changes in climate, light environment, and crop growth response, prevents imbalance in nutrient solution concentration and excessive irrigation, and enables the automation of customized irrigation management for each growth stage.

[0265] FIG. 8 shows a flowchart of an automatic correction coefficient update algorithm according to an embodiment of the present invention. Based on the irrigation control performed in FIG. 6 and the correction criteria for each growth stage in FIG. 7, the algorithm analyzes feedback data collected after the end of irrigation to automatically recalculate a correction coefficient (α) and target values ​​(EC, drainage rate, etc.), and is composed of a series of steps to reflect these values ​​in the next irrigation cycle.

[0267] Step S810 refers to the feedback data collection step. In this step, after irrigation is finished, the control unit collects feedback data such as the EC, pH, drainage rate, flow rate, moisture content recovery amount, accumulated solar radiation, and irrigation supply amount of the drainage from the nutrient solution control system (4) and the drainage recycling processing board (32). Additionally, environmental data such as the outside temperature, inside temperature, humidity, CO₂ concentration, and light intensity collected through the environment control system (3) are also acquired. These data are transmitted to the GCS server (2) to form a feedback database, and the system performs the correction calculation for the next step based on this.

[0269] Step S820 is the step of calculating the error with respect to the target value. The server compares the collected feedback data with the target values ​​(target EC, drainage rate, pH, etc.) for each growth stage defined in Fig. 7. That is, it calculates the deviation (ΔEC, ΔpH, Δdrainage rate) between the actual measured value and the target reference value for each irrigation cycle to determine whether it is excessive or insufficient compared to the set value.

[0271] For example, if the actual drainage EC is 0.2 dS / m or higher than the target EC, it is determined that the fertilizer concentration is excessive, and conversely, if it is lower, it is determined that the fertilizer supply is insufficient. These error values ​​are used as input variables for recalculating the correction coefficient in the subsequent step (S830).

[0273] Step S830 is the step of recalculating the correction factor and target value. In this step, the server recalculates the correction factor (α) and the new target value (EC′, drainage rate′) based on the error calculation results. At this time, the correction logic can be expressed as follows.

[0274] EC new = EC target + k1 ( EC target - EC drain )

[0275] αnew = f(ΔEC,ΔpH,Δdrainage rate,growth stage,solar radiation)

[0276] Here

[0277] EC_target: Target EC value set in the previous cycle (e.g., 2.0 dS / m)

[0278] EC_drain: Actual measured EC value of drainage (e.g., 2.3 dS / m)

[0279] (EC_target - EC_drain): Error relative to target (ΔEC)

[0280] k1 is an error-reflecting weight (Gain coefficient, setable in the range of 0.1 to 0.5) and is a parameter used to adjust the correction sensitivity according to the EC error (ΔEC). That is, this equation operates by reflecting the error between the target value and the actual value at a certain ratio (k₁) to automatically correct the target EC_new in the next irrigation cycle.

[0282] When the EC of the drain is higher than the target (ΔEC < 0), EC_new is lowered to induce dilution, and when the EC of the drain is lower than the target (ΔEC > 0), EC_new is higher to induce an increase in concentration.

[0284] For example, if ECtarget = 2.0, ECdrain = 2.3, and k1 = 0.3, ECnew = 2.0 + 0.3(2.0 - 2.3) = 1.91, in which case the nutrient solution is automatically corrected to be supplied at a concentration about 5% lower in the next irrigation cycle.

[0286] Accordingly, k₁ is a proportional gain coefficient that determines the response rate to error, and can generally be set to 0.1 to 0.2 during the stable period, and 0.3 to 0.5 during the high temperature, high light period, or rapid growth period. This value is automatically learned by the GCS server (2) and is variably adjusted in real time according to environmental conditions, light intensity, and growth stage, thereby preventing over-feeding and stabilizing the nutrient solution concentration simultaneously.

[0288] In addition, a new α value is calculated by considering the difference between the actual EC and the target EC of the drainage (ΔEC), environmental factors (solar radiation, temperature), and correction factors for each growth stage. The new α value is the equation used in the irrigation control algorithm (S640).

[0289] EC target = ( EC raw ×α) + (EC drain ×β)

[0290] It is reflected in the α term so that the target concentration is automatically adjusted in the next watering cycle.

[0292] In addition to EC, the present invention is configured to automatically correct the acidity (pH) and supply amount of the nutrient solution by considering deviations in pH and drain ratio.

[0293] pH correction can be performed by the following equation.

[0294] pHnew = pHtarget +k2(pHtarget - pHdrain)

[0295] Here, pH_target is the set target pH, pH_drain is the actual pH value measured in the drainage, and k₂ is the sensitivity coefficient for pH correction.

[0296] If the pH of the drainage is higher than the target (ΔpH < 0), acid correction is performed, and conversely, if the pH of the drainage is lower (ΔpH > 0), alkali correction is performed.

[0298] For example, in the case where pH_target = 6.0, pH_drain = 6.4, and k₂ = 0.2,

[0299] pHnew = 6.0 + 0.2(6.0 - 6.4) = 5.92

[0300] Calculated as such, a solution with a low acidity of approximately 0.08 units is supplied in the next cycle. This ensures that the crop's rhizosphere environment remains stable for a long period, and the ratio of acidic or alkaline component injection into the fertilizer channel is automatically adjusted.

[0302] In addition, the drainage rate is a key indicator for nutrient supply efficiency and prevention of over-supply, and is corrected by the following formula.

[0303] Rnew = Rtarget + k3(Rtarget - Rmeasured)

[0304] Here, R_target represents the set target drainage rate (%), R_measured represents the actual drainage rate measured after irrigation, and k3 represents the drainage rate correction sensitivity coefficient.

[0306] For example, in the case where the target drainage rate is 20%, the actual drainage rate is 15%, and k₃ is 0.4

[0307] Rnew = 20 + 0.4 (20 - 15) = 22

[0308] It is calculated as such, and the supply amount increases to about 22% in the next irrigation cycle. In other words, if the drainage rate is lower than the standard, the supply amount is increased to prevent salt accumulation, and conversely, if the drainage rate is excessive, the supply amount is reduced to minimize nutrient waste.

[0310] Thus, the present invention is configured to correct the concentration, acidity, and amount of nutrient solution in real time by reflecting the feedback error for each of the three main variables of EC, pH, and drainage rate in a proportional control manner, and to automatically optimize the correction coefficients (k₁, k₂, k₃) according to the crop growth stage and environmental conditions by the learning algorithm of the GCS server (2).

[0312] Next, step S840 is the server database update step. In this step, the recalculated correction factor (α_new) and target values ​​(EC_new, pH_new R_new) are updated and stored in the database of the GCS server (2). The server transmits the updated data to the UI integrated control terminal (10) and the nutrient solution control system (4) so ​​that the entire system shares the latest correction standards.

[0314] The updates performed at this stage are stored in log form and can be utilized for future irrigation performance analysis and training of optimization models based on long-term data.

[0316] Step S850 is the step for reflecting the next irrigation cycle. In this step, the server automatically applies the updated correction coefficients and target values ​​to the next irrigation control loop (S610–S660). That is, during subsequent irrigation control, the nutrient solution concentration, supply volume, and irrigation start conditions are adjusted based on these correction values. Through this, the system realizes an adaptive learning closed-loop control structure that corrects control parameters autonomously using feedback data.

[0318] FIG. 9 shows an overall flowchart of a cloud-based predictive irrigation control system according to an embodiment of the present invention. The system is structured to evaluate and optimize irrigation control performance by automatically collecting data generated from a nutrient solution control system and an environment control system into a cloud server and automatically calculating the irrigation start time, end time, supply amount per cycle, and supply interval using a machine learning-based predictive model.

[0320] In step S910, periodic data is collected from the environmental control system (3) and nutrient solution control system (4) installed at the greenhouse site, as well as from various monitoring equipment (solar radiation meter, moisture content sensor, weight scale, etc.). The collected data includes items such as ambient temperature, internal temperature, humidity, solar radiation, wind speed, CO₂ concentration, shading rate, nutrient solution EC·pH, flow rate, drainage rate, irrigation start / end time, and supply amount. This data is stored in the GCS server (2) and cloud server, for example, at intervals of 1 minute or a fixed period.

[0322] In step S920, preprocessing such as missing value correction, outlier removal, unit standardization, and time synchronization is performed on the collected raw data. Additionally, useful features (cumulative light intensity, transpiration, moisture content deviation, drainage rate relative to water volume, etc.) are automatically extracted by linking environmental data and irrigation logs. This process is performed automatically within the server's internal data pipeline, and the data structure is refined into a form suitable for input into a machine learning model.

[0324] In step S930, a dataset for inputting the prediction model for each control setting item is automatically configured using the preprocessed data. This dataset consists of the following sub-components.

[0325] (a) Dataset for predicting the start time of the first irrigation

[0326] (b) Dataset for predicting the end time of the last irrigation

[0327] (c) Dataset for predicting daily irrigation requirements

[0328] (d) Dataset for predicting single supply quantity

[0329] (e) Dataset for predicting supply intervals (based on time or cumulative light intensity)

[0330] These datasets are automatically classified by the GCS server, uploaded to the cloud server, and used as training data for models for each category.

[0332] In step S940, a prediction model is trained and executed using a machine learning environment running on a cloud server. For example, the present invention may utilize Microsoft Azure ML Studio and MLops environments, and a separate regression or classification model is built for each prediction item (irrigation start time, end time, supply amount, etc.). The cloud server periodically updates the training data to retrain the model and generates the latest prediction values ​​corresponding to new environmental conditions (temperature, solar radiation, humidity, etc.).

[0334] In step S950, the learned model is distributed in the form of an API (Application Programming Interface) to link with the nutrient solution control system and the environment control system in real time. The result of the prediction model is transmitted to the Magma Plus environment controller or the UI integrated control terminal (10) via the GCS server (2), and the irrigation start time, end time, supply amount, and interval are automatically set. At this time, the prediction result may operate in parallel with the user's manual settings, and after user approval, it may be switched to automatic mode and reflected in the control logic.

[0336] In step S960, cumulative irrigation history and environmental data for each greenhouse are periodically transmitted to a cloud server to evaluate the performance of the model and perform retraining. Performance evaluation can be performed using indicators such as Mean Squared Error (MSE), Mean Absolute Error (MAE), and Coefficient of Determination (R²). When performance degradation is detected, the MLops pipeline automatically performs retraining and redeploys the latest version of the model to the GCS server (2). Through this, the system is configured to always maintain the latest predictive control performance according to seasonal changes in the greenhouse, crop growth stages, and changes in user patterns.

[0338] Accordingly, the entire process of Fig. 9 forms a closed-loop structure of data collection -> preprocessing -> predictive learning -> API integration -> automatic update, and the present invention can adapt to environmental changes in a greenhouse in real time and maximize irrigation efficiency and growth stability by utilizing such an artificial intelligence-based predictive model.

[0340] FIG. 10 is a diagram illustrating the configuration and control flow of a drainage recycling and safety control system according to one embodiment of the present invention, wherein (A) illustrates sterilization control for drainage recycling and (B) illustrates mixing control for drainage recycling.

[0342] As illustrated in (A) of FIG. 10, the drainage recycling system consists of a pre-treatment drainage tank (101) and a post-treatment drainage tank (102) separated into multiple zones (e.g., 1 to 8), and a drainage sterilizer (103) connected between them. Each tank is equipped with a high-level sensor (104) and a low-level sensor (105) to detect the amount of drainage.

[0344] Sterilization control is performed according to the control logic of the drainage recycling controller (110). The sterilizer (103) operates only during the preset sterilization operating time (start to end time) and is deactivated at other times to prevent unnecessary energy waste and over-sterilization. The control unit determines whether the current time is within the sterilization operating time and then checks the water level status of the tank before and after treatment for each zone.

[0346] For example, if the tank (101) before treatment is in a low water level state, there is insufficient drainage to supply, so the sterilization operation in that area is restricted. If the tank (102) after treatment is in a high water level state, there is insufficient storage space, so the sterilization operation in that area is skipped.

[0348] When the conditions for sterilization are met, the control unit opens the pre-treatment tank solenoid valve (Vin) and the post-treatment tank solenoid valve (Vout) of the corresponding area so that the drainage water is circulated in the order of "pre-treatment -> sterilizer -> post-treatment".

[0350] If the sterilization time exceeds the set time for each zone, the control unit closes the valve of the current zone and opens the valve of the next zone to sequentially switch zones. Through this, multiple drainage zones are sterilized sequentially and automatically, and efficient drainage sterilization is achieved based on the water level and time conditions of each zone.

[0352] FIG. 10(B) illustrates a mixing control unit (120) of a drainage recycling system. The system of the present invention combines two flow paths flowing in from a raw water tank (121) and a post-treatment drainage tank (102) through a mixing valve (122) and performs automatic control based on the measurement value of an EC sensor (123) installed at the mixing point.

[0354] Mixing control is performed based on a comparison between the set EC (target concentration) and the measured EC (actual mixing concentration).

[0355] For example, when the measured EC > set EC, the concentration of the mixture is high, so the drainage inflow of the mixing valve (122) is blocked or reduced to induce dilution. On the other hand, when the measured EC < set EC, the concentration of the mixture is low, so the valve opening is expanded to increase the drainage inflow rate.

[0357] The mixing ratio is adjusted in real time through a PID-based proportional control loop inside the controller. At this time, by continuously adjusting the valve opening / closing step (%) and opening delay time (sec) by considering (1) absolute error, (2) cumulative error, and (3) target approximation damping coefficient together between the set EC and the measured EC, the mixed drainage is stably maintained at the target EC approximation value.

[0359] In addition, the drainage recycling rate (%) is expressed by the valve opening value, where a valve opening of 0% means 100% supply of raw water and 100% means 100% supply of drainage. For example, if the drainage EC is higher than the set value, the upper limit of the valve opening is restricted, and the drainage recycling rate is lowered, and if the drainage EC is lower than the set value, the valve opening is expanded, and the drainage reuse rate increases.

[0361] FIG. 11 shows a flowchart of a drainage recycling and safety control algorithm according to an embodiment of the present invention. The drainage recycling control system of the present invention automates a series of processes for storing, sterilizing, mixing, and resupplying drainage generated during the nutrient solution supply process, and comprehensively controls sterilization time, water level conditions, EC(pH) data, mixing ratio, and safety conditions to realize stable recycling of drainage and safe operation of the greenhouse environment.

[0363] In step S1110, the drainage recovered from the greenhouse flows into the pre-treatment drainage tank (101) and is stored in the first stage. At this time, the electrical conductivity (EC) and pH values ​​of the drainage are measured by EC / pH sensors (EC4, pH4), and the collected data is transmitted in real time to the control board (30) and the GCS server (2). The control unit determines whether the EC of the stored drainage exceeds a set allowable range (e.g., 1.5 to 3.0 dS / m), and if excessively concentrated drainage is detected, it performs the following correction logic.

[0364] - Increased drainage rate: Prevents salt concentration by shortening the nutrient solution replacement cycle in the growing medium.

[0365] - Supply volume adjustment: Dilute the supersalate drainage by increasing the supply volume per cycle.

[0366] - Interval adjustment: Induce periodic flushing by shortening the supply interval according to moisture content and light intensity conditions. This step involves the control board monitoring the concentration and moisture content of the drainage to secure basic data necessary for subsequent sterilization and recycling control.

[0368] In step S1120, a condition check is performed to determine whether the drainage sterilizer is running. First, the control unit determines whether the current time is within the sterilization operation time range by referring to the sterilizer operation time (start to end). Then, the status of the high-level sensor (104) and low-level sensor (105) installed in the pre-treatment drainage tank (101) and post-treatment drainage tank (102) of each zone is checked.

[0370] If the tank is at a low water level before treatment, sterilization of that area is restricted because there is insufficient drainage to supply to the sterilizer. If the tank is at a high water level after treatment, sterilization of that area is skipped because there is insufficient space to store the sterilized drainage.

[0372] When all sterilization conditions are satisfied, the control unit activates the sterilizer control signal for the corresponding area.

[0374] In step S1130, the actual operation of the sterilizer takes place. The control unit opens the inlet / outlet electronic valves (Vin, Vout) of the zone where the conditions are met to form a flow path of “drain tank before treatment -> sterilizer -> drain tank after treatment”.

[0376] The sterilization operation time is managed so as not to exceed the standard time set for each zone (e.g., 10 to 30 minutes), and when sterilization of each zone is completed, the corresponding valve is automatically closed and the process switches to the next zone to perform sterilization sequentially.

[0378] Status data such as the sterilizer's operating status, current value, and processing flow rate is monitored via the control board, and if a new high or low water level condition occurs during sterilization, sterilization in the corresponding area is immediately stopped and an alarm is triggered.

[0380] In step S1140, mixing control is prepared to recycle the drainage liquid during the nutrient solution supply stage. The control unit checks the water level status of the raw water tank (121) and the post-treatment drainage tank (102), and sets the initial opening value of the mixing valve (3-way valve, 122) when both are within the normal water level range. In addition, it loads the set EC (EC_set) value which serves as the EC control standard and performs initialization of the EC sensor (123) installed in the mixing line. At this time, the initial opening of the mixing valve is set to, for example, 50%, and control begins in a state where the raw water and drainage liquid are supplied at the same ratio.

[0382] In step S1150, the mixing ratio is adjusted in real time. The control unit calculates an error (ΔEC = EC_set - EC_meas) by comparing the actual mixing concentration (EC_meas) measured by the EC sensor (123) with the set target concentration (EC_set).

[0383] - When EC_meas > EC_set: Since the concentration of the mixture is excessively high, the opening of the mixing valve (122) is reduced to reduce the amount of drainage inflow and induce dilution.

[0384] - If EC_meas < EC_set: Since the concentration of the mixed liquid is low, increase the valve opening to increase the drainage inflow and raise the concentration.

[0386] At this time, the control unit dynamically adjusts the valve opening rate (%) and opening delay time (sec) by applying a PID control algorithm that includes a cumulative error (I) and a corrected damping (D) in addition to simple proportional control (P). For example, when ΔEC is -0.3 dS / m, the valve opening is reduced by 10%, and when ΔEC is +0.3 dS / m, the valve opening is expanded by 10%.

[0388] Through this, the mixing ratio of raw water and drainage is automatically adjusted in real time, and the EC of the mixed drainage is stabilized within the range of the approximate set value (±0.05 dS / m).

[0390] In step S1160, the entire control process is terminated and protection operations are performed. The control unit checks the water level sensors and sterilizer status signals in all zones; if they are in a normal state, it closes each valve and terminates the drainage recycling control.

[0392] If a low water level, high water level, sensor malfunction, or communication error is detected, the system automatically switches to Fail-safe mode, closes all electronic valves, and temporarily switches the nutrient solution supply to raw water mode (no mixing of drainage solution).

[0394] In addition, at the end of the cycle, data such as the sterilization log for each zone, the amount of change in drainage EC, the valve opening rate, and the supply amount are transmitted to the GCS server (2) and used to correct the control reference value for the next cycle.

[0396] FIG. 12 shows the main interface screen of a drainage recycling control system according to one embodiment of the present invention. The main screen of the system is an integrated irrigation management screen (UI) for integrally displaying and controlling the irrigation status of each zone in the greenhouse, real-time sensor data, accumulated light intensity information, emergency irrigation status, etc., through a central control device or a user terminal.

[0398] As described, the zone-specific irrigation status displays the irrigation volume and frequency for each zone, and the real-time sensor measurement display screen monitors real-time measurements. To control the irrigation schedule based on light intensity and crop transpiration, it is configured to present the greenhouse's irrigation management status and system operation status by monitoring the solar radiation measured within the control cycle and the time interval during which no irrigation was supplied from the last irrigation until now.

[0400] Manual watering can be supplied to active zones by user selection, regardless of light intensity or automatic watering schedules. Manual watering can be controlled by starting or stopping emergency watering to supply water to the entire zone collectively, or by specifying desired zones. The following is a brief description of the provided features.

[0402] - Set Amount: Set irrigation supply amount per zone. Supply amount unit is set per zone.

[0403] - Cumulative amount: Daily cumulative watering amount by zone

[0404] - Watering frequency: Daily cumulative watering frequency by zone

[0405] - Nitrogen Reduction Status: Whether zone nitrogen reduction is applied. (0: Not applied, 1: Applied)

[0407] - Sunrise time: Today's sunrise time

[0408] - Sunset time: Today's sunset time

[0409] - Start time: The earliest start time among the time-dispersion and solar radiation proportional groups

[0410] - End time: The slowest end time among the time-dispersion and solar radiation proportional groups

[0412] - Setting EC: Current supply setting EC for nutrient solution dispenser

[0413] - Set pH: Current supply pH of the nutrient solution system

[0414] - Current EC: The sensor EC currently being measured

[0415] - Current pH: The sensor pH currently being measured

[0417] - Current Liquid Channel Information: Information on the solenoid valve channel currently controlled by the system. A1B1, A2B2, or Dual Channel

[0418] - Liquid-to-Fluid Channel Adjustment Status: Status information on whether the solenoid valve currently controlled by the system has been switched to A1B1 or A2B2.

[0419] - Current Solar Radiation: The solar radiation value currently being measured (W / m2)

[0420] - Cumulative solar radiation: Cumulative light intensity measured on the day (J / cm2)

[0421] - 30-minute cumulative light intensity: Cumulative light intensity over the last 30 minutes (J / cm2)

[0422] - Previous day's cumulative light intensity: Cumulative light intensity measured yesterday (J / cm2)

[0423] - Medium EC: Medium EC data of the WCM installed in the nutrient solution system

[0424] - Medium Temperature: Medium temperature data of the WCM installed in the nutrient solution system

[0425] - Substrate weight: Weight data from the scale installed in the nutrient solution system

[0426] - Indoor temperature: Dry-bulb temperature data from the wet-bulb thermometer installed in the nutrient solution unit

[0427] - Indoor humidity: Relative humidity data from the wet-dry / dry bulb thermometer installed in the nutrient solution unit

[0428] - Application Cycle: Cycle information currently applied to Groups 1–4

[0429] - Group Cumulative Light Intensity: Group cumulative light intensity data currently accumulated in Groups 1–4

[0430] - Emergency Irrigation: Emergency Irrigation Start Button. Pressing the Emergency Irrigation Button while the system is in standby mode starts irrigation of the active valve area once. Pressing the Emergency Irrigation Button while the system is in operation stops the currently running irrigation.

[0431] - Emergency Stop: Emergency irrigation termination button. Pressing the Emergency Stop button during emergency irrigation stops the current emergency irrigation.

[0432] - Selected Area Emergency Irrigation: A function that designates an area among all areas to be irrigated once via emergency irrigation, allowing for selective emergency irrigation only on the designated area.

[0434] Select areas for emergency irrigation: Only the selected areas will be emergency irrigated.

[0435] Click the Selected Area Start button: Selected Emergency Irrigation Activation button

[0436] Click the Emergency Irrigation button: Select to start emergency irrigation.

[0437] Selected Area Emergency Irrigation Amount: Set the amount of water to be supplied via the selected area emergency irrigation.

[0439] The irrigation volume unit is controlled by the zone-specific irrigation unit (dripper, time, zone volume) set in the irrigation zone settings.

[0440] Selected Zone Emergency Irrigation Setting EC: Set EC to be supplied via the selected zone emergency irrigation

[0441] Selected Zone Emergency Irrigation Setting pH: Set the pH to be supplied via the selected zone emergency irrigation.

[0443] - Function to change daily and previous day's cumulative solar radiation

[0444] Current Cumulative: Today's cumulative solar radiation to set

[0445] Previous Day Accumulation: Previous day's accumulated solar radiation to set

[0446] Setting Button: A button to set the entered daily and previous day's cumulative solar radiation (this function is for testing purposes only).

[0448] FIG. 13 illustrates a monitoring screen of a nutrient solution control system according to an embodiment of the present invention. The monitoring screen of the system is configured to display key sensor data of the nutrient solution supply line and the automatic / manual status of the control device in real time, thereby allowing the user to intuitively check the operating status of the system and respond immediately to abnormal situations.

[0450] The system monitoring function displays real-time data from sensors related to nutrient solution control.

[0452] The nutrient solution dispenser can uniformly measure the EC and pH of the supplied nutrient solution using two channels of sensors in the nutrient solution supply pipe, and is configured to respond to various greenhouse environments, such as crop-greenhouse structures, by selectively changing the sensor channels for each zone according to the irrigation settings.

[0454] Pressure gauge monitoring can monitor up to six types of pressure within the system's water pipes, detecting pressure changes before and after the system's filter or sudden pressure changes before and after the discharge section, thereby monitoring system safety and maintenance timing.

[0456] A pipe thermometer is a temperature sensor inside a pipe for detecting the point of system over- or malfunction, and is a monitoring sensor for preventing system overheating and detecting malfunctions.

[0458] A tank level gauge is a sensor that detects a low water level in a tank and is used to limit operation when there is a shortage of water or fertilizer concentrate in the nutrient solution irrigation line.

[0460] Pump and solenoid valve automatic detection is a function that detects the automatic control capability of actuators within the nutrient solution control system; it is a system maintenance sensor that detects whether the local system is capable of starting when an automatic control command is generated by the system.

[0462] Each item is as follows.

[0463] - Supply EC Sensor 1 : Real-time data from EC Sensor 1 (dS / m), 5 = 0.5 due to decimal processing

[0464] - Supply EC Sensor 2 : Real-time data from EC Sensor 2 (dS / m), 10 = 1.0

[0465] - Supply pH Sensor 1 : pH Sensor 1 Real-time Data (dS / m), 20 = 2.0

[0466] - Supply pH Sensor 2 : Real-time data from pH Sensor 2 (dS / m), 25 = 2.5

[0467] - Solar radiation: Real-time solar radiation sensor data (W / m2)

[0468] - Pressure Gauge 1 : Pressure Gauge 1 Real-time Data (bar) [Dosing Channel Pressure Gauge]

[0469] - Pressure Gauge 2: Pressure Gauge 2 Real-time Data (bar) [Pressure Gauge Before Discharge Filter]

[0470] - Pressure Gauge 3: Real-time data from Pressure Gauge 3 (bar) [Pressure gauge after discharge filter]

[0471] - Pressure Gauge 4: Pressure Gauge 4 Real-time Data (bar) [Raw Water Intake Pressure Gauge]

[0472] - Pressure Gauge 5: Real-time data from Pressure Gauge 5 (bar) [Pressure gauge before recovery filter]

[0473] - Pressure Gauge 6: Real-time data from Pressure Gauge 6 (bar) [Pressure gauge after recovery filter]

[0474] - Pipe Temperature 1: Pipe Thermometer No. 1 Real-time Data (°C) [Raw Water Pump Discharge Temperature]

[0475] - Pipe Temperature 2: Pipe Thermometer No. 2 Real-time Data (°C) [Nutrient Pump Discharge Temperature]

[0476] - Pipe Temperature 3: Real-time data from pipe thermometer No. 3 (°C) [Temperature measured at drainage end of pipe]

[0477] - Raw water tank temperature: Real-time data from the raw water tank thermometer (°C)

[0478] - Raw water tank level: Raw water tank low level status (ON: Low level, OFF: Normal)

[0479] - Liquid Fertilizer Tank Level 1 : Liquid Fertilizer Tank 1 (A1) Low Level Status (ON : Low Level, OFF : Normal)

[0480] - Liquid Fertilizer Tank Level 2: Liquid Fertilizer Tank 2 (B1) Low Level Status (ON: Low Level, OFF: Normal)

[0481] - Liquid Fertilizer Tank Level 3 : Liquid Fertilizer Tank 3 (A2) Low Level Status (ON : Low Level, OFF : Normal)

[0482] - Liquid Fertilizer Tank Level 4 : Liquid Fertilizer Tank 4 (B2) Low Level Status (ON : Low Level, OFF : Normal)

[0483] - Liquid Fertilizer Tank Level 5 : Liquid Fertilizer Tank 5 (C) Low Level Status (ON : Low Level, OFF : Normal)

[0484] - Liquid Fertilizer Tank Level 6 : Liquid Fertilizer Tank 6 (D) Low Level Status (ON : Low Level, OFF : Normal)

[0485] - Raw Water Pump Manual: Raw Water Pump Manual Status (ON: Manual, OFF: Automatic)

[0486] - Nutrient pump manual: Nutrient pump manual status (ON: Manual, OFF: Automatic)

[0487] - Drainage Manual: Drainage line solenoid valve manual status (ON: Manual, OFF: Automatic)

[0488] - Solenoid Valve Manual 1:Liquid Fertilizer 1 (A1) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0489] - Solenoid Valve Manual 2: Liquid Fertilizer 2 (B1) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0490] - Solenoid Valve Manual 3: Liquid Fertilizer 3 (A2) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0491] - Solenoid Valve Manual 4:Liquid Fertilizer 4 (B2) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0492] - Solenoid Valve Manual 5:Liquid Fertilizer 5 (C) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0493] - Solenoid Valve Manual 6:Liquid Fertilizer 6 (D) Solenoid Valve Manual Status (ON: Manual, OFF: Automatic)

[0495] FIG. 14 shows an alarm status data display screen of a nutrient solution control system according to an embodiment of the present invention. This screen is configured to visually display the alarm setting status of the nutrient solution dispenser and related sensors, whether a real-time alarm has occurred, and delay time information, so that the user can recognize and respond to abnormal situations in the system at an early stage.

[0497] The main alarm status data allows checking the alarm setting status and real-time alarm occurrence status of sensors connected to the nutrient solution system. By checking the alarm function usage, alarm occurrence status, and delay time count for each sensor item, it is configured to enable early detection of sensor abnormalities, identification of the occurrence time, elapsed time, and current processing status, and may include the following items.

[0499] - Usage Status: Enabled or disabled status of the corresponding alarm setting. (ON: Enabled, OFF: Disabled)

[0500] - Alarm Status: Current alarm operation status (ON: Alarm triggered, OFF: Alarm deactivated)

[0501] - Delay Count: Current alarm delay time (seconds) for the corresponding alarm setting

[0503] - A page to check the alarm usage status and alarm occurrence of sensors that can be installed in the nutrient solution system.

[0504] - Sensors that can be installed in the nutrient solution unit are those installed on the circuit board terminals on the nutrient solution unit side, and sensors processed on the nutrient solution unit's main CPU side

[0506] The alarm status of sensors processed by the drainage-side auxiliary CPU can be checked on a separate page.

[0508] FIG. 15 shows an alarm monitoring screen of a drainage recycling system according to an embodiment of the present invention. This screen is configured to visually display the alarm setting status of sensors connected to the drainage and drainage recycling system, whether a real-time alarm has occurred, and delay time information, so as to enable early detection and response to abnormal situations that may occur during the drainage processing process.

[0510] The drainage alarm monitoring screen allows you to check the alarm setting status for each sensor in the drainage recycling system and whether a real-time alarm has occurred, and each item includes the following data.

[0511] Usage Status: Indicates whether the corresponding alarm setting is in use; ON means alarm monitoring is enabled, and OFF means it is not in use.

[0512] Alarm Status: Indicates whether an alarm is currently running from the sensor; ON means the alarm is currently active.

[0513] Delay Count: Displays the time elapsed or delay time (in seconds) since the alarm occurred, allowing the duration of the alarm and the progress of processing to be monitored.

[0515] This screen monitors sensor data (e.g., EC, pH, water temperature, low water level, etc.) from the drainage recycling zone and displays the alarm status for each tank separately before (low water level) and after (high water level) drainage treatment. The low water level alarm for the tank before treatment monitors for insufficient water input to the sterilizer, while the high water level alarm for the tank after treatment is intended to prevent overflow caused by exceeding storage capacity.

[0517] The sensors displayed on this screen are sensors connected to the drainage recycling terminal of the nutrient solution dispenser substrate, and represent alarm information processed independently by the drainage-side auxiliary CPU. Accordingly, the system of the present invention can improve the stability and operational efficiency of the drainage recycling control section by managing the alarms of the nutrient solution dispenser main control unit and the drainage control unit separately.

[0519] FIG. 16 shows a backwashing and drainage control setting screen according to an embodiment of the present invention. This screen provides a setting interface for integrally controlling raw water filter management, nutrient solution temperature control, tank heating control, and stirrer operation settings of a nutrient solution system.

[0521] In a nutrient solution system, the backwash setting is a function to maintain the filtration efficiency of the sand filter. When the amount of filtered material collected in the filter increases and the water flow rate decreases, the system automatically performs backwashing according to the operating time or a certain period to restore the filtration function.

[0523] In addition, the drainage control setting automatically opens the drainage valve when the temperature of the supplied nutrient solution exceeds the set range, preventing high or low-temperature nutrient solution from being supplied to the crops.

[0525] The raw water heating control is configured to maintain the temperature stability of the nutrient solution by activating an auxiliary heating device when the temperature of the raw water in the tank drops below a set value.

[0527] In addition, the stirrer control function includes a feature that automatically operates and stops the stirrer at set time intervals to prevent mixing of the solution and sedimentation within the fertilizer concentration tank.

[0529] The detailed composition of each item is as follows.

[0530] Backwash setting: Sets the usage conditions for the backwash function, 0 is not used, 1 is based on watering time (minutes), and 2 is based on elapsed days (days).

[0532] Backwashing Cycle: This is the cycle value for performing backwashing after a set watering time or number of days have elapsed.

[0534] Wait time after watering: Set the waiting time (in seconds) from the end of watering for the day until the start of backwashing.

[0536] Washing Time: Set the actual time (in seconds) for backwashing.

[0538] Manual Backwash / Backwash Stop: A control function that allows the user to manually start or stop the backwash.

[0540] Base Year and Count Items: Data for backwash history and cycle management, recording and displaying the last backwash date, cumulative elapsed time, remaining time, progress status, etc.

[0542] Drain pipe temperature: The temperature value (°C) of the pipe referenced for drain control.

[0544] Drain valve control setting: Sets the operating conditions of the drain valve, where 0 means not in use, 1 means high temperature discharge (draining when the set temperature is exceeded), and 2 means low temperature discharge (draining when the set temperature is below).

[0546] Set temperature and working range: Setting the reference temperature and control tolerance range for drainage control.

[0548] Maximum discharge time: The maximum duration (in seconds) for which the valve remains open after the discharge operation begins.

[0550] Raw Water Tank and Raw Water Heating Control: Displays the current temperature of the raw water tank and the heating setting conditions. If the measured temperature is lower than the set temperature by more than the operating limit, the heating device operates automatically.

[0552] Stirrer control settings: Set the start time, operating time, and stop time of the stirrer, and it operates automatically and repeatedly according to the set cycle to homogenize the mixing of the fertilizer solution.

[0554] The backwashing and drainage control setting function of the present invention is configured to optimize the water quality, temperature, and circulation status of the entire nutrient solution system to maintain stable nutrient solution quality and system efficiency even during long-term operation.

[0556] FIG. 17 shows a system view (setting, remaining, accumulated) screen according to one embodiment of the present invention. This screen comprehensively displays the operating status of the entire nutrient solution system and performs the function of comprehensively monitoring basic irrigation setting information by zone, real-time EC and pH alarm status, solar radiation and standby time information by group, emergency irrigation control, and irrigation operation status.

[0558] The system view screen displays the irrigation code, set amount, remaining amount, accumulated amount, irrigation frequency, and nitrogen reduction status for each zone, and the units and meanings of the set values ​​automatically change according to the irrigation method (hourly irrigation, dripper, flow meter, etc.).

[0560] In addition, by coding the irrigation trigger causes (time, maximum standby time, accumulated light intensity, emergency irrigation), it is possible to check in real-time by zone under what conditions the system initiated irrigation.

[0562] The main functions of each item are as follows.

[0564] Irrigation Code:

[0565] Code output based on zone-based irrigation control methods.

[0566] 16 is watering in hours (minutes:seconds), 17 is watering in dripper units (ml),

[0567] 18 represents the flow meter-based zone volume water supply (L).

[0569] Set Amount / Remaining Amount / Cumulative Amount / Watering Count: Set Amount refers to the supply amount designated for the zone, Remaining Amount refers to the amount remaining during the current supply, Cumulative Amount refers to the total supply amount for the day, and Watering Count refers to the cumulative number of waterings for the day.

[0571] Nitrogen reduction status: Indicates whether the nitrogen reduction function is applied in each zone, where 0 indicates no application and 1 indicates application.

[0573] Irrigation Code Trigger: A three-digit code identifies the cause of irrigation initiation. The hundreds digit indicates the irrigation group, and the units digit indicates the irrigation initiation condition. For example,

[0201] means "Group 1 irrigation started under the cumulative light condition," and

[0404] means "Group 3 irrigation started under the emergency irrigation condition."

[0575] Irrigation confirmation and irrigation zone: Displays whether the irrigation is currently running (0: stopped, 1: running) and the irrigation zones (1 to 8) that are currently running.

[0577] EC Alarm / pH Alarm Status: The alarm setting status of the EC and pH sensors, the alarm occurrence status, and the alarm delay time are displayed in real time to enable early detection of abnormal conditions.

[0579] Time and Round: Displays the current system time (in minutes, 0~1440) and the current time and round in progress.

[0581] Application Cycle / Group Accumulation / Group Standby: Displays the cycle number currently applied to each group, accumulated light intensity (J / cm²), and standby time (minutes) in real time.

[0583] Representative Start Time / End Time: Displays the earliest start and latest end times among the start and end times set for each group, allowing you to check the operating range of the entire irrigation cycle.

[0585] Solar Radiation Sharing Setting: Indicates the sharing status of solar radiation data; 0 means using a solar radiation meter exclusively for the nutrient solution dispenser, and 1 means receiving solar radiation data from the environmental controller. It also displays the current real-time solar radiation (W / m²) and cumulative solar radiation (J / cm²).

[0587] Communication Check: This item monitors the communication status between the touch monitor and the nutrient solution dispenser CPU. In a normal state, the value continuously increases, and it automatically resets at midnight.

[0589] Emergency Irrigation and Emergency Stop: These buttons allow you to manually start or stop irrigation for the entire area or a selected area in an emergency. Users can activate selective irrigation by selecting a specific area and pressing the "Start" button, or immediately supply water only to that area by pressing the "Emergency Irrigation" button.

[0591] Irrigation Volume / EC / pH Input: These are the setting values ​​for the nutrient solution to be supplied during emergency irrigation of the selected zone; each item is applied according to the zone's setting unit (ml, sec, L).

[0593] The system view screen of the present invention is designed to allow the overall operating status of the nutrient solution system to be checked at a glance, and monitors irrigation conditions, environmental variables, communication status, and alarm occurrences in real time, and functions as a core UI component that improves the precision and reliability of irrigation control.

[0595] FIG. 18 shows a screen for setting sensor calibration and alarm usage for a nutrient solution device according to an embodiment of the present invention. This screen provides a function to ensure precision and stability of nutrient solution control by setting the main sensors (EC, pH, temperature, pressure, solar radiation, etc.) of the nutrient solution device, the usage of the control valve, alarm conditions, control speed, correction values, etc.

[0597] Through this screen, users can specify whether sensors are installed and whether control is enabled, and activate alarm or emergency stop functions if necessary. Additionally, by inputting zero and span correction values ​​for various sensors such as EC, pH, pressure, and temperature, measurement errors can be minimized and the reliability of the control system can be enhanced.

[0600] ① Sensor Usage and Calibration Settings

[0601] Usage Status: Sets the installation and operation status of the sensor and whether to trigger an alarm.

[0602] 0: Not used, 1: Used, 2: Used + Alarm + Emergency Stop function enabled, 3: Used + Alarm only enabled (Emergency Stop disabled).

[0604] Zero: Performs zero-point correction of the measurement value by adjusting the sensor's reference value (Offset).

[0606] Span: Adjusts the sensor's measurement range (scale) to correct the ratio error of the output value.

[0608] EC1, EC2 / pH1, pH2: Set zero and span values, respectively, to precisely calibrate the measurements of the EC sensor and pH sensor.

[0610] Solar radiation: A calibration value for a solar radiation sensor used to measure light intensity, where span (e.g., 2000) represents the maximum measurement scale of the sensor.

[0612] Pressure Gauge / Temperature Sensor / Pipe Temperature: Set calibration values ​​for sensors such as pressure, temperature, and pipe temperature in the nutrient solution supply line. The sensor's zero-span values ​​must be adjusted to match actual field conditions.

[0614] ② Setting control speed and sensitivity

[0615] EC Speed ​​ / EC Fine Speed: Sets the operating interval of the EC control valve. Normal Speed ​​refers to the total control cycle interval, while Fine Speed ​​refers to the fine adjustment cycle within the deviation range.

[0617] pH Rate / pH Fine Rate: Sets the response interval of the pH control valve; the fine rate is a fine control cycle for pH deviation correction.

[0619] EC Upper Limit / EC Lower Limit: Sets the upper and lower limits of the opening ratio of the EC solenoid valve to prevent excessive solution injection.

[0621] pH Upper Limit / pH Lower Limit: Stabilizes acid control by setting the ratio of the upper and lower opening limits of the pH control valve (C-valve).

[0623] Alkaline Upper Limit / Alkaline Lower Limit: Sets the upper and lower opening limits of the pH alkaline adjustment valve (D-valve).

[0625] ③ Solenoid Valve Correction and Operation Control

[0626] Solenoid Valve Correction (A1~D): Finely adjusts the control signal output values ​​of each solenoid valve

[0627] Corrects temporal and flow rate errors between the control command and the actual valve operation. Example: Sol A1 Correction = 100 -> Correction based on a control output ratio of 100% for solenoid valve A1.

[0629] Liquid cycle: Refers to the solenoid valve control cycle. For example, 300 outputs a valve control signal every 3 seconds. A shorter control cycle results in a faster response speed, but may result in lower system stability.

[0631] Flow rate pulse: Sets the pulse input unit of the flow meter. For example, 10 is calculated as a flow rate of 10L per pulse.

[0633] ④ Astronomical Time Calculation and Environment Settings

[0634] Latitude / Longitude / GMT: Coordinate values ​​used for calculating astronomical time inside the nutrient solution dispenser, utilized in sunrise and sunset time calculations and solar radiation-proportional irrigation algorithms. Example: Latitude 3741 means 37.41°, Longitude 12701 means 127.01°, and GMT 90 means +9.0 hours.

[0636] The nutrient solution sensor calibration and alarm setting function of the present invention enables precise mixing and supply of nutrient solutions by maximizing the stability of EC and pH control and minimizing errors caused by environmental changes through precise adjustment of correction values ​​and control speeds for each sensor. Furthermore, the alarm and emergency stop functions allow for a rapid response in the event of sensor malfunctions, thereby enhancing the reliability and safety of the greenhouse control system.

[0638] FIG. 19 shows a screen for setting whether a nutrient solution device is used and for setting alarm deviations according to an embodiment of the present invention. This screen includes a function to set whether various sensors and control devices (pump, valve, pressure gauge, temperature and humidity sensor, etc.) inside the nutrient solution device are used and to set alarm conditions, and to finely adjust low concentration, high concentration, and bidirectional alarm conditions.

[0640] Through this settings screen, users can specify alarm threshold values, deviation values, and delay times for each sensor, such as EC, pH, pressure, temperature, and humidity, and can also manage alarms triggered by low water levels in the nutrient solution supply line and tank, or by switching between automatic and manual modes.

[0642] ① Setting Alarm and Alarm Conditions

[0643] Alarm Usage: Specifies whether to enable the alarm monitoring function for sensor measurements.

[0644] 0: No alarm used; 1: Low concentration alarm (alarm triggered when measured value is lower than reference value); 2: High concentration alarm (alarm triggered when measured value is higher than reference value); 3: Low / High concentration bidirectional alarm (alarm triggered when measured value is higher or lower than reference value)

[0646] Alarm Deviation: Sets the allowable deviation that triggers an alarm when the sensor measurement deviates from the reference value. For example, 50 is set so that an alarm sounds when the deviation is ±5.0 units or more relative to the reference value.

[0648] Delay Time: This setting determines whether an alarm is triggered only when the alarm condition is met and persists for a certain period of time. Example: If set to 30, the alarm is triggered only if the threshold is exceeded for 30 seconds or longer.

[0650] Set value: A reference value for each sensor (e.g., temperature 36.0℃, EC 2.0 dS / m, etc.), and if the measured value exceeds the alarm deviation from this reference, an alarm is activated.

[0652] ② Major Device and Sensor Alarm Items

[0653] EC, pH: Monitors solution concentration imbalance by setting low concentration, high concentration, and deviation conditions.

[0654] Flow Signal Cycle / Raw Water Pump / Pipe Pump / Drainage Pump: Monitors the operating status of each pump and flow meter, and generates an alarm when operating above the set value.

[0656] Pipe Temperature / Internal Temperature / Internal Humidity: Alarm function based on abnormal temperature and humidity conditions in the greenhouse environment or pipe status.

[0658] Pressure Sensor (Pressure 1~Pressure 6): Set to trigger an alarm if the pressure value for each line exceeds the reference range.

[0660] ③ Automatic / Manual Alarm and Low Water Level Alarm Settings

[0661] Manual Alarm Usage: This setting triggers an alarm if the state does not return to automatic or manual mode after a delay when the control system switches between the two states.

[0663] 0: Alarm off ; 1 or more: Alarm on and delay time (in seconds) set ;

[0665] Low Water Level Alarm Usage: This function triggers an alarm when the water level in the raw water tank and liquid fertilizer tank drops below a set threshold.

[0666] 0: Low water level alarm disabled; 1 or higher: Low water level alarm enabled and delay time (in seconds) set

[0668] ④ Usage status by valve and tank

[0669] Valve Usage / Manual Alarm: The usage status of each valve—raw water pump, nutrient solution pump, drain valve, raw water tank, and liquid fertilizer tank—can be individually specified. Each item is set in the form of "0: not in use, 1 or more: in use and alarm monitoring".

[0671] Low Water Level Alarm: Individually monitors the low water level status of each tank (A1~D liquid fertilizer tanks) and outputs an alarm if the low water level persists for longer than the set delay time.

[0673] The function of the present invention for setting the usage status of the nutrient solution device and the alarm deviation serves to improve the stability, reliability, and automation control efficiency of the nutrient solution supply system by detecting abnormal conditions early based on fluctuations in sensor measurements and performing integrated alarm and safety control for key devices such as pumps, valves, and tanks.

[0675] FIG. 20 shows a main screen for drainage recycling according to an embodiment of the present invention. This screen is an integrated control interface configured to monitor the entire system operation information, including mixing control, sterilizer operation, sensor status, and communication status of the drainage recycling system, in real time.

[0677] On the main screen for drainage recycling, the tank water level status before and after treatment of the drainage, the setting EC of the mixing valve, the opening rate, the automatic / manual operation status, and measurement data from the sterilizer, scale, and moisture content sensor (WCM) are displayed simultaneously for each zone, allowing for intuitive verification of the quality and control status of the recycled nutrient solution.

[0679] ① Zone-specific drainage mixing control items

[0680] Setting EC: Target EC value (dS / m) of the mixing valve for drainage recycling set per zone.

[0681] The set EC value is used as a reference value during automatic control.

[0683] Set Opening: The control target opening rate (%) of each zone mixing valve, calculated by the controller.

[0685] Opening Percentage: Displays the actual opening percentage (%) of the current valve in real time, allowing you to check the deviation from the set value.

[0687] Manual state: Refers to the valve control mode, 0: not in use, 1: automatic, 2: set to manual control mode.

[0689] ② Monitoring tank water level

[0690] High level status before treatment: High level detection status of the tank before drainage recycling (on: high level, off: normal).

[0692] Low water level status before treatment: Low water level detection status of the tank before drainage recycling (on: low water level, off: normal).

[0694] High level status after treatment: High level detection status of the storage tank after drainage treatment is completed.

[0696] Low water level status after treatment: Low water level detection status of the storage tank after the completion of drainage treatment.

[0698] This function enables stable management of the inflow and outflow flow of drainage during the recycling process.

[0700] ③ Sterilizer and control status

[0701] Time: Current system time (in minutes, 0–1440 minutes).

[0703] Start Time / End Time: Sterilizer operation start and end times.

[0705] Sterilization Tank Status: Displays the operating status of the tank currently undergoing sterilization.

[0707] Sterilizer Operating Status: Displays whether the sterilizer is currently operating and the zone number.

[0709] Sterilizer Count: Displays remaining sterilizer operation time or operation count.

[0711] Sterilizer Today's Cumulative: Daily cumulative operating time of sterilizers by zone (in seconds).

[0713] Drain motor initialization: Perform valve closure and operation checks upon initialization after power is applied.

[0715] ④ EC·pH Sensor Monitoring

[0716] EC3 / pH3: EC and pH values ​​measured at the measurement unit after the raw water and drainage are mixed. (Used as key reference data for drainage recycling control.)

[0718] EC4 / pH4: EC / pH sensor measurements for drainage adjustment and nutrient solution feedback, serving as auxiliary data for managing overall system concentration and acidity balance.

[0720] ⑤ Moisture content and scale-based data

[0721] Scale 1 Weight: Actual weight (kg) of the scale used to calculate the supply and drainage volumes for the root zone.

[0723] Liquid supply amount: Measured value of the set dripper liquid supply amount (ml).

[0725] Drainage discharge volume: The total amount of drainage discharged (ml), an indicator for evaluating the drainage status of the root zone.

[0727] Scale Communication: Data communication status between the scale and the nutrient solution dispenser.

[0729] WCM Moisture Content: Root zone moisture content measurement (%VWC) ? Evaluates moisture conditions around crop roots.

[0731] WCM Soil Temperature: Root zone temperature (°C) measurement.

[0733] WCM EC: Actual electrical conductivity (dS / m) measurement inside the medium.

[0735] WCM Communication Count: Count data to verify whether communication between the WCM (Soil Moisture Sensor) and the nutrient solution dispenser is functioning normally.

[0737] ⑥ Other functions

[0738] Emergency Irrigation / Emergency Stop: Control of emergency irrigation and system stop via manual intervention.

[0740] Communication Verification: Checks the real-time communication status between the main controller and the drainage control module. When communication is normal, the value continuously increases and resets at regular intervals.

[0742] USB Storage: A function to back up system operation data and drainage sensor logs to an external storage device.

[0744] The main screen of the drainage recycling system of the present invention is a monitoring screen capable of integrated real-time management of all control states of the nutrient solution recycling system. It allows for the control of EC / pH balance, verification of the status of sterilization and mixing processes, and optimization of nutrient supply based on root zone moisture content, all of which can be performed on a single screen. This maximizes the efficiency of drainage recycling and prevents excessive discharge, thereby providing the effects of reduced nutrient solution usage and reduced environmental pollution.

[0746] FIG. 21 shows a drainage recycling mixing valve setting screen according to an embodiment of the present invention. This screen provides a function to set the control mode of the drainage recycling valve for each zone and to set parameters for automatically or manually controlling the valve opening rate according to the EC (electrical conductivity) standard.

[0748] The drainage recycling mixing valve controls the opening and closing angle to reach a set target EC based on the value measured by the EC sensor, and during automatic operation, the upper and lower limits of the opening, response speed, and waiting time can be adjusted to optimize the control sensitivity and stability of the system.

[0750] ① Zone-specific mixing valve control items

[0751] EC Setting: Target EC value (dS / m) for controlling the recycled mixed water in each zone. The valve is controlled in automatic operation mode based on the set EC.

[0753] Manual Opening: Sets the opening rate (%) when opening and closing the valve in manual control mode.

[0754] (e.g., when 50 is entered, the valve remains in a half-open state.)

[0756] Usage: Zone-specific valve control mode setting.

[0757] 0: Control unused

[0758] 1: Automatic control (PID-linked control based on EC sensor values)

[0759] 2: Manual control (controlled at a fixed opening rate)

[0761] ② Automatic control parameter settings

[0762] Processing calculation cycle: Setting the time cycle for recalculating the opening rate of the mixing valve.

[0763] (Unit 100 = 1 second, e.g., 500 = valve opening recalculated every 5 seconds)

[0765] EC Range: The tolerance range (dS / m) between the set EC and the measured EC. If the measured EC is within this range, additional control is delayed.

[0767] Automatic Opening Limit: Limits the maximum opening rate (%) at which the valve can open during automatic control. Does not open beyond the set value.

[0769] Automatic opening lower limit: Limits the minimum opening rate (%) at which the valve can be closed during automatic control. Does not close below the set value.

[0771] Max Wait Time: The waiting time for opening adjustment applied when the EC difference is small (in increments of 0.1 seconds). Example: 100 = Maintain opening for 10 seconds.

[0773] Minimum Wait Time: Minimum waiting time applied when EC differences are large or there are abrupt changes (in increments of 0.1 seconds). Example: 10 = Recalculate opening after 1 second.

[0775] ③ PID Control Correction Parameters

[0776] Opening / Closing Speed ​​(Proportional Application, P-value): An item that determines the valve opening adjustment range in proportion to the difference (error) between the measured value and the set value. A higher value results in a faster response speed but increases the possibility of failure.

[0778] Error Integration (I value): A control parameter that reduces long-term deviation by correcting accumulated errors. A higher value indicates greater proximity to the target EC.

[0780] Error derivative (D-value): Corrects the rate of change of error to suppress abrupt oscillations in control. Improves system stability.

[0782] PID Proportional-Integral-Derivative Application: Indicates whether a PID algorithm is applied to automatically adjust the valve opening / closing ratio based on changes in EC deviation.

[0784] ④ System operation stability correction

[0785] Closing time: Sets the time (in seconds) required for the valve to fully open or close. Used to increase control stability when EC error decreases or increases rapidly.

[0787] Example of applying EC latitude: Set EC = 4.0 dS / m, EC latitude = 2 -> If the measured EC is in the range of 3.8~4.2 dS / m, the control signal is delayed.

[0789] The mixing valve setting function of the present invention can precisely maintain the EC of the recycled drainage mixing water through fine control based on PID control, and can simultaneously achieve stabilization of nutrient concentration in the crop root zone and nutrient-saving operation through automatic / manual mode switching and reaction speed control.

[0791] FIG. 22 shows a setting screen for a drainage recycling sterilizer according to an embodiment of the present invention. This screen is a control interface for setting and monitoring the operation cycle, start and end times, cumulative operating time, stop time, water level status, etc. of a sterilizer in a drainage recycling system by zone.

[0793] The sterilizer operates at regular intervals for the hygienic treatment of recycled drainage, and is configured to allow adjustment of sterilization operating times for each zone or automatic schedule control through this settings screen.

[0795] ① Zone-specific sterilizer control items

[0796] Sterilizer operating time: Set the actual operating time (in seconds) of the sterilizer in each zone. For example, if set to 600 seconds, the zone will perform sterilization for 10 minutes.

[0798] Sterilizer Today's Cumulative: Displays the cumulative sterilization operation time (in seconds) for each zone on the day, allowing you to check daily operation records and equipment usage.

[0800] Sterilizer Usage: Sterilizer usage settings for each zone.

[0801] 0: Unused

[0802] 1: Use

[0803] Sterilization operations are performed only in the usage area according to an automatic schedule.

[0805] ② Setting the Sterilizer Operation Schedule

[0806] Sterilizer Start Time: Set the time to start sterilizer operation in minutes (0~1440 minutes).

[0807] Example: 480 minutes = 8:00 AM (8 × 60)

[0809] Sterilizer Shut-off Time: Set the time for the sterilizer to stop operating in minutes.

[0810] Example: 1200 minutes = 8 PM (20 × 60)

[0812] Sterilizer Stop Time: Set the waiting time (in seconds) between the completion of the sterilization process and the next operation.

[0813] Example: 300 seconds = Waiting to restart after stopping for 5 minutes.

[0814] * example:

[0815] After sterilization of zones 1 to 4 is completed for 600 seconds each, the system remains stationary for 300 seconds (5 minutes).

[0817] ③ Monitoring Sterilizer Status

[0818] Sterilization Tank Status: Indicates the water level of the sterilizer tank and displays in real-time whether the level is high or low.

[0820] Sterilizer operating status: Indicates the zone number (1 to 8) currently in operation, where 0 means standby, and 1 to 8 means sterilization is in operation in the corresponding zone.

[0822] Sterilizer Count: Displays the remaining time of the sterilizer stop time (in seconds).

[0823] Example: When 91 seconds have elapsed out of a 300-second stop time, the remaining standby time is displayed as 209 seconds.

[0825] Power ON Initial Counter: A counter for managing the system initialization or sterilization module startup standby time after power is applied.

[0827] ④ Water level monitoring items

[0828] By monitoring the water level status of the sterilization tanks in each zone in real time, the tank condition before and after drainage treatment can be visually checked.

[0830] High water level before treatment: Displayed when the water level in the tank exceeds the set upper limit before sterilization.

[0832] Low water level before treatment: Displayed when the tank water level drops below the set lower limit before sterilization.

[0834] High water level after treatment: Displayed when the tank water level exceeds the upper limit after sterilization is complete.

[0836] Low water level after treatment: Displayed when the tank water level drops below the lower limit after sterilization is complete.

[0838] These four conditions are individually displayed for each zone, allowing for immediate identification of any abnormalities in the drainage inflow and outflow during the sterilization process.

[0840] ⑤ Time setting and real-time display

[0841] Year / Month / Day / Hour / Minute / Second:

[0842] It displays the system's current time and is used as the reference time for calculating the sterilization schedule and counting.

[0844] The sterilizer setting screen of the present invention allows for the independent setting of sterilization times for each zone, thereby simultaneously maintaining the hygienic quality of wastewater recycling and optimizing sterilization efficiency. Furthermore, the sterilizer's operating schedule, cumulative operating volume, standby time, and water level status can be integrally controlled and monitored on a single screen, thereby improving the stability and reliability of the wastewater recycling system.

[0846] FIG. 23 shows a sensor value view screen of a drainage sterilizer according to an embodiment of the present invention. This screen is an interface configured to display real-time measurement data collected from key sensors (EC, pH, temperature, scale, etc.) of a drainage recycling system, and to check and manage the usage status, correction values ​​(zero and span values), etc. of each sensor.

[0848] This sensor value view simultaneously displays EC, pH, and temperature data measured in real time during operation of the drainage sterilizer, as well as measurements related to the root zone, thereby enabling quick identification of the drainage quality and the operating status of the sterilizer.

[0850] ① Real-time sensor measurement items

[0851] EC3 (Drainage EC Sensor 3): Real-time measurement (dS / m) of EC Sensor No. 3 installed in the recycling drainage mixing section. Example: Displayed value 42 -> Actual 4.2 dS / m.

[0853] pH3 (Drainage pH Sensor 3): Real-time measurement of pH Sensor 3, indicating the acidity (pH) status of the drainage after mixing.

[0855] EC4 (Drainage EC Sensor 4): Real-time data (dS / m) from the EC sensor measured in the section after sterilization and control. Used as a reference value for the recycling concentration control algorithm.

[0857] pH4 (Drainage pH Sensor 4): pH sensor measurement indicating the acidity status of the drainage water after sterilization and treatment.

[0859] Temperature 1 (Raw Water): Real-time temperature value of the raw water tank (pre-treatment water storage tank).

[0860] Example: Display value 138 -> 13.8°C.

[0862] Temperature 2~Temperature 8: Real-time measurements from the backup temperature sensors (2~8),

[0863] It is possible to monitor the temperature distribution of each zone or circulation line.

[0865] ② Measurement items related to scales and flow rates

[0866] Scale 1 Weight: Real-time weight measurement (kg). Used as reference data for calculating nutrient supply and drainage amounts for the root zone.

[0868] Supply volume: Measure the real-time dripper supply volume (ml) to check the amount of supplied nutrient solution.

[0870] Drainage Discharge: Displays the amount of drainage (ml) discharged from the bottom of the slab in real time. It is possible to diagnose the absorption efficiency of the root zone by analyzing the difference with the amount of feed injected.

[0872] Scale Communication: Indicates the communication status between the scale and the controller, and the status flag is updated to 0 or 1 upon normal communication.

[0874] ③ Sensor Calibration and Usage Settings

[0875] Usage Status: Sets whether to reflect control for each sensor.

[0876] 1 = Used, 0 = Unused.

[0877] In case of a sensor malfunction, the corresponding sensor can be excluded from the control calculation.

[0879] Zero value:

[0880] Reference value for sensor initial offset correction.

[0881] Example: The reference value 210 of the EC sensor adjusts the measurement reference error to units of 2.10 dS / m during zero correction.

[0883] Span value:

[0884] A coefficient for adjusting sensitivity within the measurement range, as the upper calibration value of the sensor.

[0885] (e.g., pH sensor span 174 = calibration upper limit range 1.74 pH units)

[0887] Temperature sensor calibration: Each temperature sensor is based on zero (0) and span (1000) reference values.

[0888] The ADC converted value is corrected to be converted into the actual temperature.

[0890] ④ Real-time data monitoring function

[0891] On this screen, the measurement values ​​of each sensor are updated in real time, and the usage status, calibration values ​​(Zero / Span), and communication status of each sensor can be checked simultaneously. This allows users to monitor changes in EC, pH, temperature, feed and drainage flow rates during the drainage recycling process, and enables immediate diagnosis and calibration in the event of a sensor malfunction.

[0893] The sensor value view screen of the present invention enables real-time quality control of the drainage recycling process, detection of sensor anomalies and assistance for automatic calibration, and optimization of precise control based on nutrient solution concentration, pH, and temperature data, thereby enabling improved accuracy and stable operation of sterilization, mixing, and drainage control.

[0895] FIG. 23 shows a screen for setting whether to use the drainage and sterilizer sensor calibration and alarm according to an embodiment of the present invention. This screen is an interface for setting and managing whether to use various sensors connected to the drainage recycling system, whether to use the alarm (alarm) function, and the calibration values ​​(zero and span correction values) of the sensors.

[0897] The accuracy of measurement data can be maintained by setting the sensor's calibration value, and the low water level detection sensor before and after drainage treatment can be independently configured to determine whether to use it and whether to link it with an alarm, thereby enabling rapid detection of water level abnormalities during system operation.

[0899] ① Sensor Calibration and Usage Settings Item

[0900] Usage Status: Settings for the use and alarm functions of each sensor.

[0901] 0: Not in use

[0902] 1: Use sensor (disable alarm)

[0903] 2: Use sensor + Enable alarm function

[0905] Zero: A reference value correction item for the sensor that adjusts the sensor's initial deviation by removing the reference offset during measurement.

[0907] Span: An item for correcting the maximum sensitivity range of the sensor, which corrects the upper measurement limit from the zero reference.

[0908] (e.g., Temperature sensor span 1000 = Converts ADC value 1000 to 100.0°C.)

[0910] ② Drainage Treatment Tank Low Water Level Detection Setting

[0911] Before drainage treatment (low water level): Sets whether to use the low water level detection sensor of the tank (raw water storage tank) before treatment. It can be set to 0~2 levels, and when set to 2, the alarm (alarm) function is activated along with low water level detection.

[0913] After Drainage Treatment (Low Level): Settings for the low level detection sensor in the drainage storage tank after sterilization and recycling treatment are completed. This item can also be independently configured for usage and alarm linkage.

[0915] Each item is displayed separately for Tanks 1 through 8, and low-water level sensors in all zones can be controlled individually, allowing for real-time diagnosis of drainage status and water level abnormalities for each section.

[0917] ③ Setting Examples by Sensor Type

[0918] EC3 (Drainage) / pH3 (Drainage): EC and pH measurement sensors located before the drainage mixing stage. When the alarm is set, an alarm is triggered immediately if a deviation exceeding the standard occurs.

[0920] EC4 (drainage) / pH4 (drainage): EC·pH measurement sensor after drainage sterilization and recycling.

[0921] Used for quality monitoring in the recycling process.

[0923] Temperature 1~Temperature 8: Temperature sensors installed in the raw water and circulation lines. Consistency of temperature sensitivity is ensured through zero / span correction.

[0925] The sensor calibration and alarm setting function of the present invention improves the stability and reliability of the drainage recycling system by managing the usage status of each sensor, maintaining correction values, and activating alarms upon detection of abnormalities. In particular, by simultaneously setting the alarm function of the low-water level detection sensor before and after drainage processing, it is possible to detect imbalances in drainage circulation or pump abnormalities at an early stage, thereby significantly contributing to the uninterrupted operation and safety of the system.

[0927] FIG. 25 shows a screen for setting the usage status and alarm deviation of a drainage sterilization device according to an embodiment of the present invention. This screen provides a function to configure control parameters for automatically generating an alarm when a sensor measurement value deviates from an abnormal range by setting alarm (alarm) conditions for various sensors connected to the drainage recycling and sterilization device.

[0929] In addition, it includes a function that automatically generates an alarm if the low water level of the tank is continuously detected for a certain period of time before and after drainage treatment, enabling immediate response in the event of a system malfunction.

[0931] ① Sensor Alarm Setting Item

[0932] Usage: Enable alarm function per sensor.

[0933] 0: Alarm function disabled

[0934] 1: Low concentration (or decrease) alarm triggered

[0935] 2: High concentration (or overincrease) alarm triggered

[0936] 3: Two-way alarms for low and high concentrations (monitoring both upper and lower limits)

[0937] ※ Example: If the EC3 (drainage) sensor is set to 3, an alarm may be triggered if the measured value is higher or lower than the set value.

[0939] Alarm Deviation: Sets the threshold deviation (tolerance range) for triggering an alarm. An alarm is ultimately triggered if the sensor measurement exceeds or falls short of the set reference value by the alarm deviation and persists for a delay longer than the specified time. (e.g., Deviation 50 = Detected when exceeding reference value ±5.0 dS / m)

[0941] Delay Time: The waiting time (in seconds) before triggering an alarm. It generates an alarm only when the condition persists for longer than the set time, preventing false alarms caused by momentary noise or disturbances. (e.g., if set to 30 seconds, the alarm is triggered when the condition lasts for 30 seconds or longer)

[0943] Setpoint: The target value serving as the alarm standard. It sets monitoring criteria for each sensor, such as EC, pH, and temperature. (e.g., if set to -1, it means monitoring relative to the control reference value.)

[0945] ② Low water level alarm setting for drainage treatment tank

[0946] On the right side of this screen, a low water level detection and alarm setting function for the tank before and after drainage treatment is provided.

[0948] Use before drainage treatment (low water level): Setting the low water level detection function of the raw water storage tank before treatment.

[0949] 0: Unused

[0950] 1 or more: Alarm triggers if low water level persists for the set value (in seconds).

[0951] (e.g., 30 -> Alarm output if low water level persists for 30 seconds)

[0953] Usage after drainage treatment (low level): Setting the low level detection function of the drainage storage tank after sterilization and recycling. The setting method is the same as the low level setting before treatment, and an alarm is triggered if the low level signal is continuously maintained.

[0955] ③ Examples of monitoring by sensor

[0956] EC3 (Drainage): Monitors the EC of the recycling mixing section, and triggers an alarm if the deviation from the set value exceeds ± alarm deviation for 30 seconds or longer.

[0958] pH3 (Drainage): If the acidity (pH) deviates from the standard range, an alarm is output depending on the low concentration (acidification) or high concentration (basicization) conditions.

[0960] Temperature 1~Temperature 8: Monitors the temperature of raw water and each line, and outputs an alarm if the set temperature range (e.g., 36.0°C) is exceeded.

[0962] The alarm deviation setting function of the present invention has the effect of enhancing the stability and operational reliability of the drainage recycling process by immediately detecting abnormal conditions when sensor measurements deviate from the reference range. Furthermore, by combining the low water level detection function of the tank before and after drainage treatment, it contributes to preventing equipment damage and improving operational safety by detecting system risk situations such as pump idling, valve sticking, and water level imbalance at an early stage.

[0964] FIG. 26 shows a screen for setting the usage page of a main system function according to an embodiment of the present invention. This screen is a function selection interface configured to allow individual setting of whether to use various function modules of a nutrient solution control system (watering control, solar radiation control, schedule control, drainage recycling, etc.).

[0966] Pages for each functional unit are selectively activated based on the user's system configuration environment, control objectives, greenhouse structure, etc., allowing unnecessary control items to be disabled or specific functions to be operated independently.

[0968] ① Settings items by page function

[0969] Hourly Watering Settings: Set whether to use the page that automatically controls watering volume in time units (e.g., 1 hour, 30-minute intervals, etc.).

[0970] 0: Disable hourly watering function

[0971] 1: Use hourly watering function

[0973] Solar Radiation-Proportional Irrigation (Groups 1–4): A group-based function that automatically adjusts water volume according to changes in solar radiation. Each group is configured independently based on the cultivation environment, crop type, greenhouse location, etc., and performs precise watering control based on solar radiation data.

[0974] 0: Disable solar radiation for the corresponding group

[0975] 1: Activate solar radiation proportional watering for the corresponding group

[0977] Solar Irradiance Accumulation Speed ​​Control: A page function that automatically corrects EC and watering amounts based on changes in luminous flux, using the solar irradiance (J / 30 min) accumulated over a certain period. When the group-specific solar irradiance-EC control setting is enabled, it is configured to operate automatically regardless of the page usage setting.

[0979] Schedule Control: Sets whether to use the page for the schedule-based control function, which allows stepwise adjustment of target EC and irrigation volume by period and day.

[0980] 0: Disable Schedule Control Page

[0981] 1: Enable Schedule Control Page

[0983] Drainage Recycling Settings: Sets whether to use the drainage management system page, which performs drainage EC and pH measurement, sterilization, and recycling control. Enabling this item also activates recycling-related submenus (mixing valve, sterilizer, sensor calibration, etc.).

[0985] * example

[0986] The settings on this screen simultaneously manage the access rights to the operation page and the control activation status of each function. For example, if the user sets "Solar Irrigation Group 1" to 0, both the UI menu and control algorithm of that group are disabled, and it is excluded from automatic calculations even during system operation.

[0988] The user page setting function of the present invention allows for the selective activation of functional units tailored to greenhouse or nutrient solution control environments, thereby maximizing system configuration flexibility and user convenience. In particular, administrators can achieve operational efficiency and a customized control environment by selectively operating only solar radiation control, schedule control, or drainage recycling functions as needed.

[0990] Figure 27 shows a manual output test screen for the actuator of a nutrient solution dispenser and drainage recycling system. This screen is a start-up test interface for manually controlling or checking the operating status of each device (pump, valve, sterilizer, etc.).

[0992] Key features include manual output control for the nutrient solution valve, drainage valve, and sterilizer. With this function, you can manually send output signals to individual devices by pressing the switch for each item to check their operation status.

[0994] In addition, it provides an automatic operation stop function when entering system inspection mode. When the user activates the startup inspection page on the touch screen, the automatic control of the nutrient solution dispenser and drainage recycling system is temporarily suspended, allowing for safe manual output inspection.

[0996] The main inspection items include,

[0997] - Nutrient pump, raw water pump, solenoid valves (A1~D): Inspection of irrigation and mixing systems

[0998] - Drain Mixing Valve (Open / Closed): Check operation of drain control line

[0999] - Sterilizer (Zones 1–8): Check operation of sterilization devices and lamps for each zone

[1000] - Heater, backwasher, stirrer, etc.: May include auxiliary device operation tests.

[1002] Although preferred embodiments of the present invention have been described in detail as above, this is merely an example to aid in understanding the present invention, and those skilled in the art can make various modifications, variations, and applications without departing from the technical spirit or scope of the present invention, and it is obvious that such modified embodiments are also included within the scope of protection of the present invention. Accordingly, the scope of protection of the present invention is determined by the appended claims, and all technical ideas within the scope equivalent to the claims should be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[1004] 1: Web-based integrated control platform; 2: GCS server 3: Environmental Control System (Magma Plus) 4: Nutrient Solution Control System 10 : UI Integrated Control Terminal 20 : TCP / 232 Converter 30 : Integrated Board 31 : Nutrient Solution Treatment Board 32: Drainage recycling processing board 311: Nutrient solution input section 312: Nutrient solution treatment unit 313: Nutrient solution output unit 321 : Drainage input unit 322 : Drainage processing unit 323 : Drainage output section

Claims

Claim 1 An intelligent nutrient solution and drainage recycling control system based on root zone data analysis for smart greenhouses comprises: a nutrient solution supply unit that supplies a nutrient solution generated by mixing raw water and liquid fertilizer to a greenhouse cultivation area; a drainage collection unit including a pre-treatment drainage tank for collecting drainage discharged from the greenhouse cultivation area; a drainage treatment unit including a sterilizer for sterilizing the drainage of the pre-treatment drainage tank, a post-treatment drainage tank for storing the sterilized drainage, a mixing valve for mixing the drainage of the post-treatment drainage tank with raw water, a drainage transfer pump, and a drainage valve; a drainage sensor unit including a sensor for measuring the EC, pH, temperature, and water level of the drainage stored in the pre-treatment drainage tank, a sensor for measuring the EC, pH, and water level of the drainage stored in the post-treatment drainage tank, and a sterilizer status sensor for detecting the operation completion status of the sterilizer; and an integrated board in which a nutrient solution treatment board for controlling the nutrient solution supply unit and a drainage recycling treatment board for controlling the drainage treatment unit are arranged on a single hardware frame.It includes, wherein the nutrient solution treatment board and the drainage recycling treatment board each include an independent microcontroller and exchange data in real time by sharing a common communication bus; the nutrient solution treatment board calculates a target EC value of the nutrient solution to be supplied by the nutrient solution supply unit and transmits it to the drainage recycling treatment board; the drainage recycling treatment board uses the target EC value to correct the drainage recycling concentration and transmits the actual drainage EC value measured in the drainage tank after treatment to the nutrient solution treatment board; the nutrient solution treatment board feeds the actual drainage EC value back to the mixing ratio control of the nutrient solution supply unit; and the drainage recycling treatment board opens the mixing valve to supply the drainage from the drainage tank after treatment to the nutrient solution supply unit only when the operation completion signal of the sterilizer is confirmed, the water levels of the drainage tank before treatment and the drainage tank after treatment are within the normal water level range, and the EC and pH measured in the drainage tank after treatment are included in the set recycling allowable range; and if the operation of the sterilizer is not completed or the abnormal state of the sterilizer An intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse, characterized by closing the mixing valve and opening the drainage valve to switch to a drainage mode when EC or pH detected or measured in the drainage tank after the above processing exceeds the recycling allowable range, and when the integrated board detects a low or high water level exceeding a set safety range, a sensor malfunction of the drainage sensor unit, or a communication error between the nutrient solution treatment board and the drainage recycling treatment board, closing the electronic valve of the drainage recycling system and controlling the nutrient solution treatment board to switch the nutrient solution supply to a raw water mode where the drainage is not mixed. Claim 2 An intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse, characterized in that, in claim 1, the drainage treatment unit further includes a mixing EC sensor installed at a mixing point where the drainage from the treatment-post-drainage tank and the raw water are joined by the mixing valve to measure the EC of the mixed solution, and the drainage recycling treatment board calculates the error between the target EC value received from the nutrient solution treatment board and the measured EC value measured by the mixing EC sensor, and adjusts the opening rate and opening delay time of the mixing valve according to PID-based control using the absolute value, cumulative value, and target approximation damping coefficient of the error, and is configured to decrease the opening rate of the drainage inflow side of the mixing valve when the measured EC value is higher than the target EC value, and increase the opening rate of the drainage inflow side of the mixing valve when the measured EC value is lower than the target EC value. Claim 3 In claim 1, the pre-treatment drainage tank and the post-treatment drainage tank are provided in multiple numbers corresponding to each of the multiple greenhouse cultivation zones, and each of the pre-treatment drainage tank and the post-treatment drainage tank is equipped with a high-level sensor, a low-level sensor, and an electronic valve that controls the inflow and outflow of drainage, and the sterilizer is selectively connected to the multiple pre-treatment drainage tanks and the multiple post-treatment drainage tanks, and the drainage recycling processing board checks the water levels of the pre-treatment drainage tank and the post-treatment drainage tank of each greenhouse cultivation zone within a set sterilization operating time, restricts the sterilization operation in the greenhouse cultivation zone where the pre-treatment drainage tank is in a low-level state, skips the sterilization operation in the greenhouse cultivation zone where the post-treatment drainage tank is in a high-level state, and for the greenhouse cultivation zone where the sterilizable water level condition is satisfied, opens the electronic valve on the pre-treatment drainage tank side and the electronic valve on the post-treatment drainage tank side of the corresponding greenhouse cultivation zone so that the drainage is the pre-treatment drainage tank, the sterilizer, and the post-treatment An intelligent nutrient solution and drainage recycling control system based on root zone data analysis for a smart greenhouse, characterized by moving in the order of drainage tanks, and, when the sterilization time set for the corresponding greenhouse cultivation zone has elapsed, closing the electronic valve of the corresponding greenhouse cultivation zone and opening the electronic valve of the next greenhouse cultivation zone to sequentially perform sterilization for the plurality of greenhouse cultivation zones. Claim 4 delete Claim 5 delete

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