• Journal of Biosystems Engineering
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• 제31권4호
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• pp.334-341
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• 2006

This study designed to develop a mower which can reach to side of a tractor or inclined road side and operate weeding. The prototype consists of 4 parts; the base and turning equipment, the boom, the arm, the weeder. The hydraulic actuators were divided into two operations, weeding and operation of boom and they were controlled by electrical equipment. Weeding was very effective when pressure set up at $15{\ell}/min$ using weeding, as $2.27kg{\cdot}m$, 2,210rpm. Weeding range of flail mower was 1.1 to 2.6m from the center of turning equipment at a flat. In case of disk mower, it was 1.5 to 2m. As a result of operation test, flail mower was appropriate for weeding at fence and short weeds, disk mower was appropriate for long weeds.

• Journal of Biosystems Engineering
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• 제26권6호
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• pp.517-524
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• 2001

Steep and narrow ramp installed in the paddy field makes it difficult and sometimes dangerous to drive agricultural machines on it. Because agricultural machinery become larger and heavier, it is necessary to revise design standard for ramp to provide safe travel. This study was conducted to revise the design standard fur paddy field ramp, especially for its width and slope. A mathematical model predicting travelling path of a tractor on paddy field ramp and farm road was developed and simulated. To verify this model, field tests were carried out. The model could predict trvelling path with RMS Error of 12.5cm and 8.2cm, which were judged to be adoptable fur determining the width of paddy field ramp. By applying this model to 110ps tractor, which was assumed to be the largest tractor in Korea, width of paddy field ramp was determined as over 3.6m. The slope of paddy field ramp, which provided tractor with 10% of the total weight of the tractor and the mounted implement as reaction force at front wheel against ground was analyzed by considering weight transfer effect on a ramp. The result showed that adequate slope of paddy field ramp was 14°.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권4호
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• pp.343-356
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• 2011

This paper proposes an accelerated life evaluation of drive shaft. The life test of drive shaft for independent suspension type AWD vehicle should be performed by use of the least test sample because many number of samples can't be used for the test because of its mass capacity and high price. We calculated the no failure test time by application of no failure test concept, and the already performed test data for drive shaft are applied for some kinds of reliability coefficients which are needed for calculation of life test time. And, for analysis of real driving condition of vehicle, the load spectrum is prepared using the needed road condition and vehicle data. The inverse power model is used for accelerated life test. The equivalent torque of load spectrum is achieved by use of Miner's Rule, and then the final accelerating condition is determined by decision of the accelerated test torque. This paper shows that the accelerated life test results corresponds with the target life and the proposed life test method can be very well applied to no failure life test for mass capacity machinery components.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.1055-1062
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• 1996

A method for automatically driving paddy vehicles, such as rice transplanters, etc., straight ahead in a paddy field was investigated . The direction of such vehicles must be precisely controlled to do the operations as straight. However, the alignment of the from wheels becomes distorted due to the unevenness of the ground, preventing the vehicle form going straight. If the proper alignment of the front wheels is maintained , the vehicle can be driven straight ahead greater precision. To investigate the influence of the ground uneveness, the behavior of a paddy vehicle running over an obstacle was quantified. The left wheel ran over an obstacle on a flat concrete road surfaced. When the steering wheel was free, the front wheels were forced toward the left when vehicle went up the obstacle and toward the right when the vehicle went down it. The torsion of the wheel when the vehicle went down the obstacle was larger than that when it went up ,so it turned right 5 degrees. Sinc hydraulic control steering decreased the steering angle , it turned right 3 degrees. These results suggest that a vehicle can be driven straight ahead with high precision when the steering angle is changed in response to the direction and inclination of the vehicle . Such results were obtained in a paddy field tests.

• 한국자동차공학회논문집
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• 제25권2호
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• pp.227-235
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• 2017

In this paper, a systematic 5-mode(road steering, all-wheel steering, crab steering, reduced swing out mode and independent steering) steering algorithm design process for an all-terrain mobile crane with 5 axles and all steerable wheels is proposed. Steering angles for each steering mode are designed based not only on basic theory but also on vehicle specification, design limitation and requirements. A multi-body dynamic analysis is carried out to investigate the feasibility of the steering algorithm. According to the results, the proposed steering algorithm meets the objective of each steering mode.

• 동력기계공학회지
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• 제15권6호
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• pp.11-15
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• 2011

This study investigated the symptoms of the a reduction in output while driving on the road, or increasing of fumer out exhaust gas on inclined road while working air-conditioner in summer. Notice how the experiment in 2010, the Ministry of Environment(Chapter No. 2010-46), and how the vehicle emissions inspection was carried out. 2500cc Diesel cars used in the study were used and compare to output of engine, exhaust gas, inhalation temperature measurement Inhalation of cold air has not been supplied to all agencies when comparing the results when cold air intake temperature of the supply air-conditioning switch range control from 1 to 4, the temperature drops $98^{\circ}C$ to $78^{\circ}C$. At the momentum of switch level 4, output from 63ps to 66ps after the connection has increased 9.6 percent, the highest concentration of exhaust emissions were reduced by 42.8%. This research can contribute in part to the reduction of exhaust directly supply into the cooling air intake line, doing the output of diesel cars in the summer. In addition, construction equipment and machinery that are currently being used excluding the engine's intercooler cooling of the supply line via a separate output in the summer and help reduce exhaust emissions is expected.

• 농업과학연구
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• 제38권1호
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• pp.121-128
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• 2011

I/An electro-hydraulic transmission having advantages of convenience, safety, simple linking and high power, and an electronic control system were designed and fabricated. In this study, characteristics of the control system were investigated through outdoor tests for evaluation of installation of the system on a combine. Major findings were as followings. 1. Experiment for performance evaluation of the control system was conducted on concrete road. With steering lever in neutral position, driving HST swash plate and left/right wheel speed increased in proportion to driving lever angle. In case of steering control, steering swash plate angle changed in proportion to steering lever angle. This should cause increase in outer wheel speed, but it was observed that HST swash plate was controlled toward neutral to maintain the speed before steering. As a result, speed before steering was maintained despite the change in outer wheel speed by steering HST swash plate angle change. 2. It was observed that the HST system enabled steering with outer wheel maintained at constant speeds while inner wheel speed decreased, which was more stable than conventional mechanical links. In addition, for the selected 5 criteria, experiment showed satisfactory results and it was judged that installation on real vehicle would be feasible. 3. The control system showed response property of appropriate forward/reverse movement and lift/right steering, without causing any problems during experiment on concrete. Result of response property experiment on field operation also showed appropriate control over forward/reverse movement and left/right steering.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.124-131
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• 2000

In this study, the NEURAL NETWORK (hereinafter referred to as NN) was applied to control of the nonlinear factors for turning movement of the crawler vehicle and experiment was carried out using a small model of crawler vehicle in order to inspect an application of NN. Furthermore, CHAOS NEURAL NETWORK (hereinafter referred to as CNN) was also applied to this control so as to compare with conventional NN. CNN is especially effective for plane in many variables with local minimum which conventional NN is apt to fall into, and it is relatively useful to nonlinear factors. Experiment of turning on the slope of crawler vehicle was performed in order to estimate an adaptability of nonlinear problems by NN and CNN. The inclination angles of the road surface which the vehicles travel on, were respectively 4deg, 8deg, 12deg. These field conditions were selected by the object for changing nonlinear magnitude in turning phenomenon of vehicle. Learning of NN and CNN was carried out by referring to positioning data obtained from measurement at every 15deg in turning. After learning, the sampling data at every 15deg were interpolated based on the constructed learning system of NN and CNN. Learning and simulation programs of NN and CNN were made by C language ("Association of research for algorithm of calculating machine (1992)"). As a result, conventional NN and CNN were available for interpolation of sampling data. Moreover, when nonlinear intensity is not so large under the field condition of small slope, interpolation performance of CNN was a little not so better than NN. However, when nonlinear intensity is large under the field condition of large slope, interpolation performance of CNN was relatively better than NN.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.89-98
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• 1999

In this paper, to estimate the effectiveness of the tractive performance prediction model(TPPMTV98) which was developed to predict the tractive performance of flexible tracked vehicles in previous paper, the experimental substantiation of the TPPMTV98 were conducted with the reconstructed tracked vehicle on the loam soil with the moisture content of 18.92%, and bevameter was constructed in order to measure soil properties in situ. The drawbar pulls measure were compared with predicted ones. As a result, the predicted drawbar pulls by the TPPMTV98 were well matched to the measured ones. Such results implied that the TPPMTV98 could well estimate the drawbar pulls at given soil conditions, and would be very useful as a simulation tool for designing a flexible tracked vehicle and predicting its tractive performance.

• International journal of advanced smart convergence
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• 제6권2호
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• pp.16-23
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• 2017

In contemporary modern society, people are constantly exposed to many kinds of noise, such as that from machinery, aircraft, construction sites, or road traffic. Noise is considered one of the most indispensable and influential parts of human life. This study investigates the acoustic characteristics of noise transfer from external sources to the human ear. For this study, we measured and analyzed various types of noise environments, installed monitoring speakers in a semi-anechoic room, and conducted intentional noise-filled experiments. In this environment, the size of the sounds generated by use of a portable device was also measured and the SNR (signal to noise ratio) calculated to study the influence of the noise. As sound is transmitted to the ear and the human body, it affects not only auditory damage but also other parts of the body. In this paper, we propose a proper SNR for noise emitted by portable IT equipment to prevent hearing loss when IT equipment is used.