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농업 4륜 전기 자동차 설계를 위한 환감 기어의 부하 분석
알리모하마드 ( Mohammod Ali ),이슬람나피울 ( Md. Nafiul Islam ),레자나심 ( Md Nasim Reza ),초두리밀론 ( Milon Chowdhury ),이슬람수마이야 ( Sumaiya Islam ),이현석 ( Hyun-seok Lee ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1
The load analysis of gears is a major challenge to ensure the reliability of the power transmission system of the all-wheel-drive electric vehicle. It is necessary to select the proper material and face width for design the reduction gears to avoid its failure during field operations. Therefore, this study aimed to investigate the suitable materials and dimensions, to evaluate the fatigue life regarding the level of damage. A field experiment was conducted on the off-road conditions following the driving speeds. A load (torque) measurement method was established to collect the torque data using torque sensors and data acquisition systems. A load duration distribution (LDD) method was used to analyze the torque data to examine the cyclic load characteristics. The Palmgren-Miner cumulative damage model was used to determine the fatigue damage level of the reduction gears. The hypothetic fatigue life was recorded up to 2500 hours that satisfied the actual service life of the agricultural vehicle. In order to the analyses, the steel material ‘SCr420H’ with a 5 mm face width gear was suitable for a 10-year vehicle service life. The results presented in this study can suggest the service life of a four-wheeled electric vehicle for agricultural use.
Measurement of pepper plant height and canopy area using 3D LiDAR point cloud
알리모하마드 ( Mohammod Ali ),카림레자울 ( Rejaul Karim ),카비르사자둘 ( Sazzadul Kabir ),구란다즈아스라푸자만 ( Ashrafuzzaman Gulandaz ),레자나심 ( Nasim Reza ),선저스틴 ( Justsung ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2
Plant height and canopy area are crucial plant factors for growth and yield monitoring. A significant number of plants at different heights and canopies are required to evaluate the plant phenotyping characteristics, which is labor-intensive and time-consuming. Therefore, the aim of this study was to use 3D LiDAR point clouds to assess the height and canopy area of pepper plants. A LiDAR (VLP-16) was installed in the experimental field to collect the 3D point clouds of pepper plants. The collected data was preprocessed with 3D point cloud data processing software. The automatic segmentation methods were tested on 13 pepper plants to calculate the height and canopy area. The 3D LiDAR point clouds used in the measuring method were compared to the manually gathered ground truth to determine the accuracy of the results. The average plant height and canopy area were found to be 66±4.5 m and 0.48±0.11 m2, respectively, by manual measurement, whereas the 3D point cloud data processing algorithm showed less accuracy. The R2 values were found to be more than 0.89 for the individual phenotypic traits. The results showed that the proposed system could automatically segment and measure plant height and canopy area. The findings of this study would contribute to further research for upland crop growth and yield monitoring.
알리모하마드 ( Mohammod Ali ),아스라푸자만구란다즈 ( Gulandaz Md Ashrafuzzaman ),레자나심 ( Md Nasim Reza ),하비네자엘리에젤 ( Habineza Eliezel ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.1
To ensure the durability of gears a fatigue analysis is essential to avoid failure during field operations under various dynamic loads. Therefore, the objective of the study was to conduct a theoretical fatigue analysis of spiral bevel gear to calculate the service life of the power transmission part of a utility track vehicle that is under development. A field experiment was performed to measure the applied load (torque) of the gear in various agricultural operations. A torque measurement system was developed to collect the axle torque data of the vehicle. The load duration distribution (LDD) method was applied to analyze the torque data to assess cyclic load characteristics. The Palmgren-Miner cumulative damage model was employed to predict fatigue failure levels of spiral bevel gears. The fatigue life under an empty platform with the driver, a lawnmower, a sprayer-trailer (150-L payload), and a lawnmower and 150-L payload trailer was recorded from 13,000 to 25,000 h approximately, which was a sufficient lifespan range of gears for 12-years service life. According to the analyses, the gears met the standard service life during field operations with attached implements. The results provided in this study can be used to design power transmission systems of utility vehicles for multipurpose agricultural operations.
알리모하마드 ( Mohammod Ali ),레자나심 ( Nasim Reza ),초두리밀론 ( Milon Chowdhury ),구란다즈아스라푸자만 ( Ashrafuzzaman Gulandaz ),키라가샤픽 ( Shafik Kiraga ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2
Multi-purpose platform of a machine performs various agricultural operations that can reduce labor and enhance the convenience of aged people and women. To obtain the maximum working efficiency and reliability of a prototype machine, a field experiment is required. Therefore, the purpose of the study was to evaluate the performance of a electric-drive tracked platform based on the power and pulling force analysis to conduct the major agricultural operations in different load and speed conditions. Grass mowing, and chemical spraying operations were selected as primary agricultural activities to evaluate the performance of the prototype tracked-platform. A data acquisition system was established with a torque sensor and a load cell to measure the maximum torque and pulling force. To record the working speeds of the platform, a global positioning system (GPS) was used. The field experiment was conducted on sandy clay loam soil condition on a 50 m operational path and the maximum speed was recorded up to 8 km/h (1 to 8 km/h). The average power requirements for a whole system (lawnmower + sprayer-trailer), a sprayer-trailer filled with 150 L of water, a lawnmower (without sprayer-trailer), and a platform itself were 1.27±0.35, 1.70±.13, 0.93±0.21, and 1.45±.19 kW, respectively. The maximum pulling force was measured 1.98±1.12, 0.614±0.46, and 19.28±11.32 kgf for hauling the rear trailer at 150L-payload condition, and 0.81±0.60, 0.416±.34, and 4.50±3.88 kgf at the unloaded condition in X, Y, and Z direction, respectively. The highest amount of average power and pulling force were recorded at maximum load condition. The power and pulling force requirements were fluctuated due to the effects of the different driving speeds. This study would help to provide information to the manufacturer for advance modifications of the tracked-platform.
Development of soil water content monitoring system using Raspberry Pi and Arduino communication
하비네자엘리에젤 ( Eliezel Habineza ),알리모하마드 ( Mohammod Ali ),아흐메드샤리아르 ( Shahriar Ahmed ),레자나심 ( Md Nasim Reza ),장영윤 ( Young Yoon Jang ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2022 한국농업기계학회 학술발표논문집 Vol.27 No.2
Soil water content is a key requirement for plant growth and development. Monitoring the soil water content continuously at several locations may offer accurate water variability data for irrigation scheduling. The aim of the study was to design and fabricate an automated data acquisition system for monitoring the variations of soil water content within the experimental soil bin through Raspberry Pi and Arduino serial communication. For evaluating the sand soil water content variability, a soil bin test bench (3m*3m) containing sandy soil was built and 90 soil water content sensors were inserted at different depths of 10, 20, 30, 40, and 50 cm, respectively. For water supply in the soil bin, a drip irrigation system containing 3 rows (60 cm inter-row distance) with 5 drippers each pipeline with 30 cm intervals, was designed. Raspberry Pi (Pi4 model B+) and three Arduino (Mega 2560) were interfaced with sensors and the data were obtained using python programing language. The data was automatically recorded in the external Pi-memory for further processing and remote monitoring was performed using a Raspberry Pi VPN system. During the experiment, the maximum and minimum averages of the ambient temperature, humidity, and the soil water content values were recorded and found to be 42.1±3 to 32.7±3°C, 75±2 to 42.9±4% and 60.91±2 to 26.95±1%, respectively. The water content percentages varied at different depths of sandy soil due to pressure difference, flow rate, and water infiltration rate. The designed automatic irrigation monitoring system would help to monitor water variability in soil.
자주식 양파정식기 슬라이딩 메쉬형 기어박스의 동력전달 해석
이슬람나피울 ( Md Nafiul Islam ),알리모하마드 ( Mohammod Ali ),키라가샤피크 ( Shafik Kiraga ),초두리밀론 ( Milon Chowdhury ),권행주 ( Haing-ju Kwon ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1
An appropriate gearbox selection is essential to avoid transmission losses and convey the engine power to the transplanter components efficiently. Therefore, the objective of this research was to simulate the power transmission of a self-propelled onion transplanter gearbox for calculating the power loss and efficiency. The automatic transplanter power transmission scheme consists of wheels, and dibbling mechanism, and picking mechanism. A computer-aided gear efficiency calculation software package was used to develop a three-dimensional simulation model for the automatic onion transplanter. A V-belt with pulley and nine gear stages sliding mesh type gearbox were used to transmit power from engine to wheel and other transplanter components. The last two gear sets were used as dibbling and picking mechanism gear shafts, respectively. The transmission load was measured at the input shaft of the gearbox, and the driving axle load was measured at the final drive shaft. The load measurements were made at three-speed levels. The input power of the gearbox was 1.7 kW, and the last stage of power (picking scheme) was found as 0.8 kW. The overall efficiency of this gearbox was found as 83.39%. The outcomes of the research would provide a significant reference for the development a power transmission scheme for efficient automatic onion transplanting.
초두리밀론 ( Milon Chowdhury ),레자나심 ( Nasim Reza ),알리모하마드 ( Mohammod Ali ),고란닺앗라퐂자만 ( Ashrafuzzaman Gulandaz ),권행주 ( Haing-ju Kwon ),정선옥 ( Sun-ok Chung ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2
The development of a riding-type automatic onion transplanter could be effective in improving the mechanization rate in onion cultivation, where the working speed analysis plays a vital role and determines planting performance and efficiency. The objective of this study was to select a suitable working speed of a 12 kW self-propelled riding-type automatic onion transplanter for efficient planting of onion seedlings with minimum damage. The proposed transplanting mechanism consisted of six assembling units of picking, conveyors, and rotary planting mechanism, where every rotary planting unit needs a continuous supply of onion seedlings at a certain rate for uniform and upright plantation. To enable the smooth collection and plantation of onion seedlings, analysis was carried out via a mathematical working trajectory model of the planting mechanism, virtual prototype simulation, and validation tests using a physical test bench. In the mathematical model analysis and simulation, the suitable rotational speed was found as 60 rpm and it was able to transplant 60 and 120 seedlings/min using the single and double unit assembly of planting mechanism, respectively. A 130 mm/s forward speed of the transplanter was preferable in terms of seedling uprightness and low damage. A forward speed of 130 mm/s with a transplanting speed of 120 seedlings/min was preferable in terms of achieving a high degree of seedling uprightness. A field test using the real prototype of the onion transplanter would be necessary to verify the accuracy of these findings.