Real-Time Autonomous Responsive Plant Growth Supplemental Lighting Device Using Embedded Sensors and Microcontrollers

Abstract

The present invention relates to a real-time, independent, responsive plant growth supplemental lighting device utilizing an embedded sensor and a microcontroller. By collecting external natural light data in real time and automatically controlling the LED light intensity using a Buck Topology-based constant current LED driver, it can stably maintain the target light intensity required for plant growth. Furthermore, it enables high-precision light intensity control by simultaneously performing PWM-based dimming control and DAC-based reference current control, and by applying a sensor noise removal algorithm based on an SMA filter and a median filter. It is applicable to a smart farm integrated control system that includes RS-485-based multi-node communication capabilities.

Description

Technology Field

[0001] The present invention relates to a real-time independent responsive plant growth supplemental lighting device using an embedded sensor and a microcontroller, and more specifically, to a real-time independent responsive plant growth supplemental lighting device that detects the external natural light environment in real time using an embedded illuminance sensor and a microcontroller, and automatically corrects the amount of light required for plant growth by independently controlling an LED light source using a buck topology-based constant current DC / DC converter, wherein an individual lighting unit detects the amount of light itself and precisely supplements only the amount of light that is insufficient. Background Technology

[0003] With the recent expansion of the smart farm and plant factory industries, the importance of supplemental lighting devices for precisely controlling the light environment necessary for plant growth is increasing.

[0004] Generally, in greenhouse environments, LED lighting is used to supplement insufficient light during periods of low sunlight or in environments with significant fluctuations in solar radiation.

[0005] However, most existing LED supplemental lighting systems operated using simple timer-based lighting or fixed output methods, which had the problem of being unable to respond to real-time changes in natural light.

[0006] Furthermore, existing technology had several problems, including the inability to adjust LED light intensity in real time according to changes in natural light, unstable LED output current due to insufficient constant current control capabilities, difficulty in precise light intensity control as only simple PWM dimming was applied, light intensity control errors caused by sensor noise and disturbances, and difficulty in integrated control among multiple LED control nodes.

[0007] In particular, since external solar radiation fluctuates frequently in smart farm environments, technology is required to automatically supplement only the amount of natural light lacking. While LED output current stability, light intensity uniformity, energy efficiency, and long-distance communication stability are simultaneously required, existing technologies have been limited by focusing on simple illuminance control or simple LED driver technology, failing to adequately provide a real-time, natural light-adaptive independent control structure.

[0008] Conventional smart farm supplemental lighting systems adopt a centralized control method to control all lighting collectively based on sensor data installed outside the greenhouse. As a result, they fail to address localized shading (such as shadows from structures) in specific areas within the greenhouse, leading to uneven crop growth. Furthermore, they have critical drawbacks, including high initial installation costs due to complex control wiring and the paralysis of the entire system in the event of a central server failure.

[0009] Prior art Patent Registration No. 10-1036869 relates to lighting control technology using an illuminance sensor, but does not disclose a constant current-based LED driver or a composite light intensity control technology combining PWM and a DAC.

[0010] In addition, Patent Registration No. 10-1496707 relates to a converter technology for reducing inrush current generated when power is applied, and does not include a real-time natural light-responsive light intensity control function.

[0011] In addition, Patent Registration No. 10-1603251 relates to constant current LED driving technology, but does not include a light intensity control algorithm based on real-time natural light adaptive control and sensor noise removal.

[0012] In addition, Patent Application No. 10-2023-0056079 relates to LVDC-based power distribution technology, and its technical configuration differs from that of an independent responsive supplemental lighting device for plant growth. Prior art literature

[0014] 1. Patent Registration No. 10-1036869 (Title of Invention: Illuminance Control System for Energy-Saving LED Lighting) 2. Patent Registration No. 10-1496707 (Title of Invention: LED Lighting with a Converter Capable of Improving Inrush Current and Dimming Control) 3. Patent Registration No. 10-1603251 (Title of Invention: Converter for LED Lighting with Constant Current Output Type and LED Lighting Device Applying the Same) 4. Patent Application No. 10-2023-0056079 (Title of Invention: Passive Beamformer Antenna for 5G FR2 and Communication Method Using the Same) The problem to be solved

[0015] The present invention aims to provide a solution to the aforementioned problems by independently determining the optimal supplemental lighting amount based on the surrounding light environment. Its purpose is to provide a real-time, independent, responsive plant growth supplemental lighting device utilizing an embedded sensor and a microcontroller that innovatively reduces energy consumption, ensures uniform growth within the greenhouse, minimizes installation and maintenance costs, and enables uniform supplemental lighting even in localized shaded areas (such as structural shadows) within the greenhouse. means of solving the problem

[0017] A real-time independent responsive plant growth supplemental light device (S) using an embedded sensor and a microcontroller according to the present invention for achieving the above-mentioned purpose comprises an input power supply unit (100) that supplies input power, a DC / DC converter unit (200) that drives an LED at a constant current using the input power, a current sensing unit (300) that detects the LED output current, an MCU control unit (400) that performs PWM-based light intensity control, a DAC control unit (500) that controls the LED reference current, an illuminance sensor unit (600) that collects external natural light data, and a light intensity control algorithm unit (700) that automatically controls the LED light intensity based on real-time light intensity data.

[0018] The above MCU control unit is characterized by being configured to independently and automatically control the LED output amount according to changes in natural light.

[0019] In addition, the DC / DC converter section (200) is characterized by including a Buck Topology-based constant current converter structure including a switching element, an inductor, and a current sensing resistor.

[0020] In addition, the MCU control unit (400) is characterized by simultaneously performing PWM duty control and DAC-based reference current control to control the LED light intensity in a combined manner.

[0021] In addition, the light intensity control algorithm unit (700) is characterized by performing an SMA filter and a median filter to remove noise and correct outliers in the illuminance sensor data.

[0022] In addition, the MCU control unit (400) receives LED output current data detected from the current sensing unit (300) in real time and controls the LED output current in a closed-loop manner by comparing the output current of the DC / DC converter unit (200) with a reference current and automatically correcting the PWM Duty and DAC output values.

[0023] In addition, the light intensity control algorithm unit (700) is characterized by calculating the difference between the current natural light brightness and the target light intensity and automatically correcting the LED light intensity by the amount of insufficient light intensity.

[0024] In addition, the communication unit (800) includes an RS-485-based serial communication function and is characterized by being configured to transmit and receive light quantity data and control data between a plurality of plant growth supplemental light device nodes and a central control system.

[0025] In addition, the plant growth supplemental lighting device is characterized by having a plurality of units configured independently to perform different LED light intensity control according to individual illumination environments. Effects of the invention

[0027] The real-time independent responsive plant growth supplemental lighting device using an embedded sensor and a microcontroller of the present invention, designed to achieve the above objectives, can optimize energy efficiency by automatically turning off the light or lowering the output when natural light is sufficient, thereby reducing electricity costs by up to 80% compared to existing methods. It also provides economic efficiency in construction by reducing installation costs by more than 30% through the implementation of 'plug and play,' which allows for immediate operation simply by connecting the power without the need for separate control line work. Furthermore, due to independent control at the individual unit level, stable system operation is facilitated as the operation of the entire system is not affected even if a specific device fails. Additionally, it offers the effects of high-precision light intensity control through PWM and DAC-based composite light intensity control, closed-loop-based real-time output correction, and RS-485-based smart farm integrated control. Brief explanation of the drawing

[0029] FIG. 1 is an overall system configuration diagram showing a preferred embodiment of the present invention. FIG. 2 is a circuit diagram of a Buck Topology-based constant current LED Driver showing a preferred embodiment of the present invention. FIG. 3 is an MCU-based PWM light intensity control block diagram showing a preferred embodiment of the present invention. FIG. 4 is a DAC-based reference current control circuit diagram showing a preferred embodiment of the present invention. FIG. 5 is a flowchart of a real-time light intensity control algorithm showing a preferred embodiment of the present invention. FIG. 6 is a flowchart of an SMA Filter algorithm showing a preferred embodiment of the present invention. FIG. 7 is a flowchart of a Median Filter algorithm showing a preferred embodiment of the present invention. FIG. 8 is an RS-485-based multi-node communication configuration diagram showing a preferred embodiment of the present invention. FIG. 9 is a circuit diagram showing the series connection configuration of an LED module and the connection relationship of a current sensing resistor, illustrating a preferred embodiment of the present invention. Specific details for implementing the invention

[0030] Hereinafter, a real-time independent responsive plant growth supplemental light device (S) using an embedded sensor and a microcontroller provided by the present invention will be described according to the attached drawings and preferred embodiments.

[0031] The present invention relates to an independent responsive LED supplemental light device that automatically corrects the amount of light required for plant growth in real time. By measuring the external natural light environment in real time and automatically controlling the LED light amount to compensate for the lack of natural light, energy efficiency can be improved and the light environment required for plant growth can be stably maintained. Each LED supplemental light node can operate independently, and multiple supplemental light nodes can be connected via an RS-485-based communication network to be linked with a smart farm central control system. The device is largely composed of an input power unit (100) that supplies input power, a DC / DC converter unit (200) that drives an LED at a constant current using the input power, a current sensing unit (300) that detects the LED output current, an MCU control unit (400) that performs PWM-based light amount control, a DAC control unit (500) that controls the LED reference current, an illuminance sensor unit (600) that collects external natural light data, and a light amount control algorithm unit (700) that automatically controls the LED light amount based on real-time light amount data.

[0032] The above MCU control unit is configured to independently and automatically control the LED output amount according to changes in natural light.

[0033] The above input power supply unit (100) receives external DC power and transmits it to the DC / DC converter unit (200). The input power can use 24V DC power, and can be configured to include an input capacitor (210) to remove input noise.

[0034] Additionally, the DC / DC converter unit (200) converts the DC voltage supplied from the input power unit (100) into a constant current form suitable for driving the LED and maintains the LED output current constant by applying a Buck Topology-based switching converter structure. It can be configured to include a Buck Topology-based constant current converter structure including a switching element, an inductor, and a current sensing resistor, and performs a switching operation based on a PWM signal generated by the MCU control unit (400) and a DAC reference current value.

[0035] In addition, the DC / DC converter unit (200) may include an LED Driver Controller (220), a MOSFET (230), an inductor (240), a freewheeling diode (250), a current sensing resistor (260), and an output capacitor (270).

[0036] The above input capacitor (210) performs the role of removing ripple noise from the input power supply and mitigating instantaneous voltage fluctuations, and improves system stability by compensating for the instantaneous current demand that occurs during switching operation.

[0037] That is, the input capacitor (210) reduces input voltage ripple, thereby improving the switching stability of the MOSFET (230, Metal-Oxide-Semiconductor Field-Effect Transistor) and consequently increasing the LED output current stability.

[0038] The LED Driver Controller (220) is a core control element that controls the switching operation of the Buck Converter. It is a system that supplies electricity to the LED and controls the brightness of the light by detecting the LED output current in real time and adjusting the switching duty of the MOSFET (230) by comparing it with the reference current. The brightness of the LED is determined by the 'current'. If this current is slightly excessive, the LED burns out, and if it is insufficient, the light becomes dim or flickers.

[0039] In other words, since external voltage (e.g., outlet voltage) can fluctuate depending on the situation, the driver filters out this voltage and performs a constant current precision control function that supplies only the constant current preferred by the LED, a dimming control function that controls the flow of power by switching it hundreds of thousands of times per second to freely adjust the brightness of the light, and a protection function that monitors situations where the LED and driver may fail, such as overheating, overcurrent, or short circuits, and immediately cuts off the power to protect the device in the event of an abnormality.

[0040] The above MOSFET (230, Metal-Oxide-Semiconductor Field-Effect Transistor) operates as a PWM (Pulse Width Modulation) based switching element and transfers energy to the inductor (240) by high-speed switching of the input power, and the LED output current is determined according to the ON / OFF time of the MOSFET.

[0041] As increasing the MOSFET switching duty increases the average LED output current and decreasing the duty decreases the output current, increasing the PWM duty (Pulse Width Modulation Duty Period) leads to an increase in MOSFET ON time, inductor energy storage, LED current, and light intensity.

[0043] During the switching process of the above inductor (240), it stores and releases energy to continuously maintain the LED output current and reduces output current ripple, thereby improving constant current characteristics.

[0044] When the MOSFET is ON, the inductor stores energy, and when it is OFF, the stored energy is supplied to the LED output section (900). Thus, current continuity is maintained during energy storage / release, the LED current is stabilized, and the amount of light is stabilized at the same time.

[0045] The above freewheeling diode (250) provides a circulating path for the inductor current during the MOSFET OFF period, thereby preventing abrupt interruption of the inductor current and improving system efficiency.

[0046] It maintains current continuity by allowing the inductor current to continuously flow to the LED output even when the MOSFET is OFF.

[0047] The above current sensing resistor (260) performs the role of converting the LED output current into a voltage form and detecting it, and the detected voltage is transmitted to the LED Driver Controller (220) and the MCU control unit (400).

[0048] When the LED output current increases, the voltage across the current sensing resistor increases, and the control unit uses this to correct the output current and maintain a constant current.

[0049] The output capacitor (270) performs the role of reducing LED output voltage ripple and noise, and by reducing output ripple, reduces instantaneous fluctuations in LED light intensity and improves light output stability.

[0050] The above current sensing unit (300) measures the LED output current in real time and transmits it to the MCU control unit (400), and enables closed-loop based automatic output correction by providing real-time feedback on the LED output status.

[0051] In addition, the above MCU (Micro Controller Unit) control unit (400) can be considered a core control unit that controls the entire system by simultaneously performing PWM duty control and DAC (Digital-to-Analog Converter)-based reference current control to comprehensively control the LED light intensity, and performs functions such as PWM generation, light sensor data collection, current data analysis, DAC control, light intensity calculation, filter algorithm execution, and communication control.

[0052] That is, by detecting changes in natural light and simultaneously analyzing the LED current status, calculating the target light amount, performing PWM / DAC control, and automatically correcting the LED light amount, the LED output current is controlled in a closed-loop manner by receiving LED output current data detected from the current sensing unit (300) in real time and comparing the output current of the DC / DC converter unit (200) with the reference current to automatically correct the PWM Duty and DAC output values.

[0053] The above DAC control unit (DAC Control Unit, 500) performs the role of converting the digital control signal of the MCU into an analog reference voltage, and the DAC output voltage is used as the reference current setting value of the LED Driver Controller.

[0054] As the DAC output voltage increases, the LED reference current increases and the LED output light intensity increases; specifically, as the DAC output increases, the reference current, LED output current, and light intensity all increase.

[0055] The above-mentioned illuminance sensor unit (600) measures the brightness of external natural light in real time and transmits the measurement data to the MCU control unit (400).

[0056] When the brightness of natural light decreases, the MCU increases the LED light intensity, and when the natural light increases, it decreases the LED light intensity. Specifically, when natural light decreases, the MCU calculates the insufficient light intensity and increases the LED light intensity to perform adaptive supplemental light control.

[0057] The light intensity control algorithm unit (700) automatically calculates the LED light intensity by comparing the target light intensity with the current natural light state, and removes sensor noise and outliers by performing an SMA Filter (Simple Moving Average) and a Median Filter. By calculating the LED light intensity using accurate illuminance data after removing sensor noise, the light intensity control error is reduced.

[0058] In other words, by filtering sensor data, calculating the accurate light intensity, and controlling a stable LED to stabilize the plant growth environment, the difference between the current natural light brightness and the target light intensity is calculated, and the LED light intensity is automatically corrected by the amount of insufficient light.

[0059] In the present invention, the average value can be calculated using the following formula.

[0060] SMA(n) = [x1 + x2 + x3 + ... + xN] / N

[0061] Here, xN represents the input value from the illuminance sensor, and N represents the number of samples used for the average calculation.

[0063] In addition, the communication unit (800) includes a UART (Universal Asynchronous Receiver / Transmitter, digital direct communication) or RS-485-based serial communication function and is configured to transmit and receive light amount data and control data between a plurality of plant growth supplemental light device nodes and a central control system.

[0064] Multiple LED supplemental lighting nodes can be connected to a central control server, and the central server can collect the light intensity status of each node and transmit control commands; specifically, after collecting the node status, it receives it from the central integrated control to manage the entire light environment of the smart farm.

[0065] The above LED output unit (900) irradiates light necessary for plant growth and may include a red LED, a blue LED, or a white LED array, and the amount of LED light changes according to the change in LED output current, which directly affects the plant growth environment.

[0066] The LED output unit (900) of the present invention has an LED module structure in which a plurality of LEDs are connected in series, as shown in FIG. 9. At this time, a current sensing resistor (260, Rsense) for detecting the LED output current (I_LED) is arranged in series in the lower (LED-) path of the LED module.

[0067] The current sensing resistor (260) converts the LED output current (I_LED) into a voltage form and detects it. The detected voltage signal is transmitted to the LED Driver Controller (220) and the MCU control unit (400) and used as reference data for closed-loop control that feeds back the LED output current in real time.

[0068] In addition, the above-mentioned plant growth supplemental light device (S) is characterized by being configured independently in multiple units, each performing different LED light intensity control according to individual illumination environments.

[0069] Meanwhile, although embodiments of the present invention have been described, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components without departing from the spirit of the invention as described in the claims, and such modifications and changes shall also be deemed to be included within the scope of the rights of the present invention. Explanation of the symbols

[0071] S: Supplemental device 100: Input Power Supply 200: DC / DC Converter 210: Input Capacitor 220: LED Driver Controller 230: MOSFET 240: Inductor 250: Freewheeling diode 260: Current sensing resistor 270: Output capacitor 300: Current sensing unit 400: MCU control unit 500: DAC control unit 600: Illuminance sensor unit 700: Light intensity control algorithm unit 800: Communication unit 900: LED output unit

Claims

Claim 1 The device comprises: an input power supply unit (100) that supplies input power; a DC / DC converter unit (200) that drives an LED at a constant current using the input power; a current sensing unit (300) that detects the LED output current; an MCU control unit (400) that performs PWM-based light intensity control; a DAC control unit (500) that controls the LED reference current; an illuminance sensor unit (600) that collects external natural light data; and a light intensity control algorithm unit (700) that automatically controls the LED light intensity based on real-time light intensity data. The light intensity control algorithm unit (700) is configured to calculate the difference between the current natural light brightness and the target light intensity to calculate the insufficient light intensity and to automatically correct the LED light intensity by the calculated insufficient light intensity. The MCU control unit (400) is configured to control the LED light intensity in a complex manner by performing PWM Duty control and DAC-based reference current control based on the insufficient light intensity calculated by the light intensity control algorithm unit (700). The MCU control unit (400) is configured from the current sensing unit (300) A real-time independent responsive plant growth supplementary light device using an embedded sensor and a microcontroller, characterized by being configured to control the LED output current in a closed-loop manner by receiving detected LED output current data in real time and automatically correcting the PWM Duty and DAC output values ​​by comparing the output current of the DC / DC converter unit (200) with a reference current, and wherein a plurality of plant growth supplementary light devices are configured to perform different LED light amount control according to individual illumination environments. Claim 2 A real-time independent responsive plant growth supplemental light device using an embedded sensor and a microcontroller, wherein, in claim 1, the DC / DC converter unit (200) includes a Buck Topology-based constant current converter structure comprising a switching element, an inductor, and a current sensing resistor. Claim 3 delete Claim 4 A real-time independent responsive plant growth supplemental light device using an embedded sensor and a microcontroller, wherein, in claim 1, the light intensity control algorithm unit (700) performs an SMA Filter and a Median Filter to remove noise and correct outliers in the illuminance sensor data. Claim 5 delete Claim 6 delete Claim 7 A real-time independent responsive plant growth supplementary light device using an embedded sensor and a microcontroller, characterized in that, in claim 1, the communication unit (800) includes an RS-485-based serial communication function and is configured to transmit and receive light amount data and control data between a plurality of plant growth supplementary light device nodes and a central control system. Claim 8 delete

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