수경 작물 재배 시스템의 양액 조제에 영향을 미치는 요인 식별

밀론초두리 ( Milon Chowdhury ),카말라술 ( Kamal Rasool ),모하마드알리 ( Mohammod Ali ),나딘알리칸 ( Nadeen Ali Khan ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

Automatic target hydroponic solution preparation is still a critical issue as several factors affect this process. The objective of this study was to identify the major factors affecting the target nutrient solution preparation, in terms of nutrient mixing method, coefficients identification, and stock solutions supply rate, for hydroponic crop cultivation. A hydroponic nutrient solution preparation test bench was fabricated, which consisted of sensors, tanks, pumps, pipes, and a controller. Two control methods, on/off and PID, were implemented and coefficients of the relevant control methods, dead-band for the on/off, and Kp, Ki, Kd for the PID method, were identified through mathematical simulations. Validation tests were performed to select the suitable control method along with their coefficients based on the response time and steady-state error. Effects of different stock solution supply rates (0.03, 0.05, and 0.1 Lmin-1) on the control methods were also evaluated. In the on/off and PID control method, the target ion concentration was maintained with the errors of 22.15% and -1.241%, respectively. Considering 2% dead-band for on/off method, and tuning the PID coefficient, the steady-state error reduced to 1.175% and -0.398%, respectively. In the case of on/off control, duration of oscillation and overshoot volume were increased with stock solutions supply rate. In the PID control, the low supply rate (0.03 Lmin-1) showed the minimum steady-state error (-0.402%), but took a long time to reach steady (364s). The Rising time for the high supply rate (0.1 Lmin-1) was short (89s), but the steady-state error was high (-1.363%). The results indicate that the nutrient mixing method, relevant coefficient/s identification, and supply rate of the stock solutions need to be adjusted system-specifically.

자주식 양파정식기 단일 호퍼형 회전식 점파 메커니즘의 작업속도 시뮬레이션

카말라술,나피울이슬람,모하마드알리,밀론초두리,권행주,정선옥 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

The dibbling mechanism for onion transplantation is a major key component to obtain required deposition of the seedling into the soil. Obtaining a suitable dibbling mechanism play an important role for the development of other mechanisms. Therefore a number of parameters need to be optimized by simulation in order to design a dibbling mechanism. The purpose of this study is to perform simulation using software package to develop a gear driven hopper type rotary dibbling mechanism for self propelled onion transplanter. The dibbling mechanism comp rises by the three main parts primary arm, connecting arm, and rotary dibbling hopper. Both in primary and connecting arms, two stage spur gears mechanisms were installed, three gears each arm. The ratio between driver and idler gear of primary arm is 1.2:1 and in the connecting arm the ratio between the idler and driven gear is 2:1. Different trials of simulation analysis were conducted using SolidWorks software to calculate the optimal working speed of the dibbling mechanism which satisfy the smooth vertical deposition of the seedling for standard plant interval. The drive shaft rpm ranging from 40 to 70 and the working speed ranging from .05 m/sec to 0.28 m/sec were considered. In order to identify the planting condition visuality, The planting trajectory for dibbling mechanism were drawn. The peak velocity and acceleration were observed 0.8 m/sec and 5.5 m/sec2 respectively. Working speed and planting rate of the mechanism for smooth vertical deposition of the seedling were found to be 0.13 m/sec for the plant interval of 7cm at 60 rpm. The seedlings will be subjected to damage if working speed is over 0.13m/sec. This proposed single hopper dibbling mechanism could plant 60 seedling/min at the depth of 35 ± 5mm. The outcomes of this study would provide a significant references for the development of an efficient onion transplanting.

농업용 4륜 전동운반차 설계를 위한 동력전달장치 모델링 및 시뮬레이션

모하마드알리,나피울이슬람,카말라술,밀론초두리,나딤알리칸,이현석,정선옥 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

The power transmission system of machine is investigated in order to optimize the important power transmission parts and their functionalities. However, the modelling and simulation of power transmission unit of the proposed four-wheeled electric cart is necessary. Therefore, the objectives of the study were to model the gears and to simulate the power transmission efficiency prior to development of the four-wheeled electric cart. The three-dimensional models of a 24, 27, and 30 T spur gear for front wheels, and 15, 20, and 25 T of bevel gear for rear wheels were modelled using steel material SM45C, employing the commercial software. The power transmission efficiency was calculated varying the gear teeth number, the input torque values, and the geometry of the gear following the directions of the power drive line. The gear module 2.68, 1.34 and 3.2, 1.6 were used to model the spur gear and bevel gear, respectively following the 1:1 gear ratio. 30, 60, 90, 120, and 150 Nm torque were applied for calculating the power transmission efficiency and loss of the proposed cart. The simulated results of 2.68 module with 27 T spur gear, and 3.2 module with 20 T of bevel gear showed the better performance compared to 24 and 30 T of spur gears as well 15, and 25 T of bevel gears for front and rear wheel, respectively. The maximum power transmission efficiency was recorded 99.96 % for the front wheel and 99.92 % for the rear wheel when applied 90 Nm torque. The simulation results presented in this study would offer a suggestion to design and develop a four-wheeled electric cart for agricultural use.

온실 내 온습도환경관리를 위한 제어인터페이스 성능평가

장영균 ( Young-kyun Jang ),카말라술 ( Kamal Rasool ),밀론초두리 ( Milon Chowdhury ),정재혁 ( Jae-hyeok Jeong ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

우리나라는 과채류, 화훼 등의 작물을 집약적으로 생산하는 시설원예 온실이 1950년대부터 2000년도까지 온실 규모가 급증가하였다. 국내에서는 2000년도 이전부터 네덜란드의 ICT 기반의 스마트팜 기술이 도입된 스마트 온실이 보급, 활용되었고, 시설원예 환경관리를 위한 복합환경제어기는 대부분 네덜란드, 이스라엘 등의 수입산이며, 초기 구축비용이 고가제품으로 고장시 수리 또한 힘들어 실질적으로 농가가 사용하는 불편함이 많이 겪고 있는 실정이다. 본 연구에서는 이러한 문제점을 해결하기 위해 온실 내부 구동기가 센싱 값에 따라 자동제어가 가능한 H/W를 설계, 제작하고, 자동제어알고리즘을 적용하여 PID 제어방법으로 온실 내 온습도 관리 여부를 확인하고자 한다. 위와 같은 문제를 해결하기 위해 제어인터페이스를 저가형으로 오픈소스 형태이고 간편 교체가 가능한 아두이노 마이크로컨트롤러를 사용하고, 제어장치의 고장문제를 해결하기위한 릴레이 교체 또는 추가를 통해 손쉽게 구동기 교체가 가능하도록 10A 릴레이를 이용하여 하드웨어를 설계 및 제작하였다. 제어인터페이스는 온실 내외부의 온습도 환경요인을 센서를 통해 자동 측정하고, 제어기에 입력된 환경관리 목표값에 따라 각종 구동장치를 가동시켜 온실 내부의 환경을 최적 관리하며, 센싱 값에 대한 구동기가 희망온도 27℃, 희망습도 60%를 설정하고 온도를 관리하는 유동팬, 냉난방기, 습도를 관리하는 제습기, 가습기를 작동시킨 결과, 1시간 이내에 온도 5%, 습도가 오차범위 2% 이내에서 지속적으로 유지되는 것을 확인할 수 있었고, 목표 수치에서 온습도 변화에 따라 잦은 구동이 반복되기때문에, PID 제어방법을 이용하여 온도, 습도의 상호작용을 통한 정밀제어가 가능하다는 것을 확인하였다.

스마트 온실 환경 제어를 통한 사용자 편의성 향상 및 센서 인터페이스 개발을 위한 기초 테스트

산다윙 ( Sandah Wing ),모하마드알리 ( Mohammod Ali ),밀론초두리 ( Milon Chowdhury ),카인미얏트시 ( Khine Myat Swe ),정재혁 ( Jae-hyeok Jeong ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

Greenhouse technologies are becoming popular for its crop production capabilities in adverse climatic conditions, however, farmers are still facing difficulties to control the ambient environment due to lower-grade sensor interface. The objective of this study is to do the basic tests of sensors for developing an interface for the user comfort and ease during the ambient environment control of greenhouses. A survey was conducted for selecting the required sensors considering their principles, and specifications. Three kinds of temperature, humidity, and carbon dioxide sensors, two kinds of soil water content sensor, a light intensity sensor, a solar radiation sensor, a rain gauge, a wind speed sensor, and a wind direction sensor are selected for the test. A circuit diagram was designed, and the power input, signal output, and response time of each sensor were checked. Based on the results, additional devices, such as power stabilizer, AD converter, resistor, were selected. The input power fluctuated on an average from 0.05 to 0.5 V, and the relevant signal output voltage varied from 0.1 to 1.2 V. Most of the sensors showed a quick response (i.e., 25μs, 1.25μs, 0.025s, and 0.05s). Results indicate that input power has a great influence on signal output and response time. A power converter could be needed to supply a stable power using a switching diode, resistors and capacitors. The developed sensor interface would be able to measure environmental parameters more accurately using any kind of sensors and increase the ease of users.

IoT를 이용한 사막 토양에서의 벼 재배를 위한 센서 기반 자동관개제어 시스템

모하마드알리 ( Mohammod Ali ),카말라술 ( Kamal Rasool ),밀론초두리 ( Milon Chowdhury ),정재혁 ( Jae-hyeok Jeong ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.1

Automatic irrigation according to the water demand is an efficient way to manage the water loss and ensure the rice quality and productivity in desert soil. Therefore, the aim of the study was to develop a sensor-based automatic irrigation control system for rice production in desert soil using Internet of Things (IoT). Field experiment was conducted in tropical desert area located at United Arab Emirates University (UAEU) farm site at Al-Foah, Al-Ain, UAE. A Linux based VPS system on Raspberry Pi 3 model B+ platform was used to implement the irrigation control unit. Python programming language was used for automation purpose. Commercial soil water content sensor (ECH20 EC-5) and relays were interfaced with the raspberry GPIO pins which were responsible to switch motor on/off. The water content percentage (%) ranging from 25~30% were considered for the rice growth in the desert soil. The output value of the water content sensors were posted and stored on the dedicated web server. The irrigation system operated based on the developed algorithm which autonomously maintain the required soil water content level in the dessert soil depending on their out put values. The pump were observed to be in operation when soil water content level dropped down below the 25% and vice versa. The proposed study based on IoT helped to display the current water content (%) and the status of pump operation (on/off). The smart irrigation system would be suitable to monitor the moisture content for rice cultivation in desert soil.

자주식 양파정식기 정식 메커니즘에 따른 기구학적 해석

카말라술 ( Kamal Rasool ),나피울이슬람 ( Md. Nafiul Islam ),모하마드알리 ( Mohammod Ali ),밀론초두리 ( Milon Chowdhury ),임승진 ( Seung-jin Lim ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.2

The demand of the onion transplanter is increasing in Korea as mechanization rate of the transplantation is less than 2% ~ 5%. Seedling transplanting mechanism is the key component of onion transplanter. Therefore, kinematic analysis of transplanting mechanism is helpful to determine the operational efficiency and performance of the implement. The purpose of this study is to develope kinematic models and simulation analysis of three different transplanting mechanisms. Five bar transplanting mechanism with pushing type seedling extraction, five bar transplanting mechanism with pin type seedling extraction, and four bar transplanting mechanism with clamp type seedling extraction were considered and their motions were simulated using commercial software. Selection of the appropriate link combination was done by conducting five numbers of trials for each mechanism with different lengths of link bars. The simulated velocities and accelerations of the end effector for each mechanism in the ‘X’ and ‘Y’ directions for appropriate link combination were found as 0.3 m/sec, 0.5 m/sec, 0.36 m/sec, 0.73 m/sec, 1.29 m/sec. 1.27 m/sec and 3.9 m/sec2, 1.6 m/sec2, 4.5 m/sec2, 4.7 m/sec2, 7.34 m/sec2, 7.26 m/sec2 respectively. The maximum seedling extraction rates were found as 60, 60 and 30 seedlings per minute, respectively. The five bar transplanting mechanism with pushing type seedling extraction could be considered as appropriate picking mechanism for onion seedling transplantation at 60 rpm speed of the driving link.

농업용 소형 궤도차량 동력전달시스템 효율성 분석

모하마드알리 ( Mohammod Ali ),나피울이슬람 ( Md. Nafiul Islam ),카말라술 ( Kamal Rasool ),밀론초두리 ( Milon Chowdhury ),나딤알리칸 ( Nadeem Ali Khan ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2020 한국농업기계학회 학술발표논문집 Vol.25 No.2

Optimization of the power transmission parts is essential for the development of a multi-functional platform for an agricultural track vehicle. However, the goals of the study were to design the gears and to evaluate the power transmission efficiency using computational simulation methods. The 3D models of a 10, 20, 30, 40, 50T spiral bevel gear were generated using steel material SM45C, employing the commercial software. The power transmission efficiency was calculated varying the gear teeth number, face width, and motor speeds maintaining the electric vehicle powertrain directions. The gear modules of 2.2, 2.7, and 3.2 were used to design the selected gears following a 1:1 gear ratio. The power transmission efficiency of the introduced vehicle was simulated using 1000, 2000, 3000, and 4000 rpm speeds. The simulation results of a 3.2 mm module with 50T showed better performance with maximum power loss at a high rotational speed. The maximum power transmission efficiency was recorded to be 99.95% when adjusted for 4000 rpm rotational speed. The designed gears with 30 mm and 20 mm face width achieved 99.91% and 99.93% transmission efficiency, respectively. The software-based analysis of power transmission gears would provide guidelines for the optimal design of the introduced agricultural utility vehicle.