• 농업과학연구
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• 제42권1호
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• pp.63-71
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• 2015

Path planning is an essential part for traveling and mowing of autonomous lawn mower tractors. Objectives of the paper were to analyze operation patterns by a skilled farmer, to extract and optimize waypoints, and to demonstrate generation of formatted planned path for autonomous lawn mower tractors. A 27-HP mower tractor was operated by a skilled farmer on grass fields. To measure tractor travel and operation characteristics, an RTK-GPS antenna with a 6-cm RMS error, an inertia motion sensing unit, a gyro compass, a wheel angle sensor, and a mower on/off sensor were mounted on the mower tractor, and all the data were collected at a 10-Hz rate. All the sensor data were transferred through a software program to show the status immediately on the notebook. Planned path was generated using the program parameter settings, mileage and time calculations, and the travel path was plotted using developed software. Based on the human operation patterns, path planning algorithm was suggested for autonomous mower tractor. Finally path generation was demonstrated in a formatted file and graphic display. After optimizing the path planning, a decrease in distance about 13% and saving of the working time about 30% was achieved. Field test data showed some overlap, especially in the turning areas. Results of the study would be useful to implement an autonomous mower tractor, but further research needs to improve the performance.

• 한국항행학회논문지
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• 제26권5호
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• pp.338-343
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• 2022

항공무선표지소는 항공이동통신시설(U/VHF송수신기) 및 다양한 항행안전시설을 통해 항공기에게 하늘길을 만들어 주고 안전하게 비행할 수 있도록 도와주는 역할을 하고 있다. 항공기에게 정확하고 안전한 신호를 끊김없이 제공해야 하기 때문에 주변의 큰 수목이나 잡초등을 제거할 필요가 있다. 조경시설의 효율적 관리를 위한 예초작업 중 예초기(Lawn Mower)에 의한 잡음 유입으로 관제업무에 지장을 초래하는 사례가 발생하고 있다. 이에 따라, 예초기가 항공이동통신시설에 어떤 영향을 주는지 분석하기 위해 4행정, 2행정, 배터리형 3가지 종류의 예초기를 대상으로 항공이동통신시설에 대한 간섭 영향 분석을 진행하였고 분석 결과 2행정 예초기가 항공이동통신시설에 크게 영향을 미친다는 점을 알 수 있었다.

• Journal of Mechanical Science and Technology
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• 제18권8호
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• pp.1401-1417
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• 2004

Experimental and computational studies were performed to determine the effects of different blade designs on a flow pattern inside a double-spindle counter rotating mower deck. In the experimental study, two different blade models were tested by measuring air velocities using a forward-scatter LDV system. The velocity measurements were taken at several different azimuth and axial sections inside the deck. The measured velocity distributions clarified the air flow pattern caused by the rotating blades and demonstrated the effects of deck and blade designs. A high-speed video camera and a sound level meter were used for flow visualization and noise level measurement. In the computational works, two-dimensional blade shapes at several arbitrary radial sections have been selected for flow computations around the blade model. For three-dimensional computation applied a non-inertia coordinate system, a flow field around the entire three-dimensional blade shape is used to evaluate flow patterns in order to take radial flow interactions into account. The computational results were compared with the experimental results.