• 드라이브 ㆍ 컨트롤
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• 제12권1호
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• pp.15-20
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• 2015

For testing a newly designed ship's steering gear, a steering gear test bench with a steering gear to be tested and a load generation part should be prepared. The load given to the steering gear has to be pertinent to the load generated in a targeted ship. In this study, the authors suggest a process of estimating the load given to steering gears in ships. At first, a test for measuring the load in the steering gear of a real ship was conducted. Then, a process was developed to compute rudder driving torque and force by using basic equations including some empirical equations on ship's steering. The test results and the computation results on the load in the steering gear were compared, As a result, the process suggested in this study for estimating load in ship's steering gears was verified.

• 한국안전학회지
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• 제12권3호
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• pp.17-22
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• 1997

This paper reals with the structure and function of duel mass flywheel. Damping effects of engine rotational fluctuation are compared with those of pre-damper clutch and duel mass flywheel and driven- system behavior is estimated engine idle r.p.m. The reason of gear rattle noise is higher in summer than winter and driving longer period than initial driving is due to affection by drag torque changing. The above-contents can be used on the design of clutch system and transmission matching including engine and duel mass flywheel.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.66-72
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• 2005

The working tactor of this study, an agriculture machine, is consisted of 4 wheel driving system with gear trains and 4-type wheel steering system. Since technological regions for 4 wheel driving system and 4-type wheel steering system are some large, we divide on two studies on 4 wheel driving system and 4-type wheel steering system This study develops transmission and axle that are very important units for strong working operation because the power of tractor is largely affected by transmission and axle. Even if the development of the power train is some common technology, it is very complicated work and needs many experience know-hows. So, for new given specifications fitted to the working tractor, a kind of new agriculture machine, this study haws out processes that are development of assembly drawing and strength analysis through classical method and CAE software for all internal parts and housing cases.

• 한국자동차공학회논문집
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• 제7권6호
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• pp.182-197
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• 1999

Described in this paper is an optimal driving control algorithm which focused on the improvement of fuel economy and the minimization of pollutant emissions in the parallel type hybrid drivertrain system for transit bus. For the energy balance among components such as engine, induction machine and buttery, the algorithm for power split ration determine is proposed. When it is implemented in the hybrid electric control unit(HECU) , using the sub-optimal method and the approximate technique , it is possible to save the memory , to shorten the calculation time, and to achieve the efficient driving actually. A Shift strategy for automated manual transmission is the other side of the driving control algorithm. It enables to select the optimal gear by using several shift maps which were predefined from the proposed method in this paper, As a results of driving simulation, it is proved that these algorithms make the hybrid drivetrain system to reduce fuel consumption and emissions considerably and to have the ability to the efficient use of battery.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.305-308
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• 2002

The mechanics, electronics and manufacturing technology have been developed rapidly. Nowadays vehicle stability becomes more and more important then ABS (Anti-lo7k Brake System), ASR (Anti-Slip Regulator), TCS, (Traction Control System), ESP (Electronic Stability Program), and VDC (Vehicle Dynamic Control) which actively control the vehicle stability actively has been improved. In this study, instead of automatic transmission, CVT (Continuously Variable Transmission) is used because of the continuously gear ratio changes. It can effectively transfer the torque from engine to tire more than other gear transmission. The modeling is simplified assuming that there are no resistance parameters.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.52-58
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• 2014

To improve the performance of clutch actuator of clutch-by-wire system for commercial vehicles, it is necessary to understand the driving characteristics of the system. To explain and predict the effects of driving characteristics on clutch characteristics, AMESim software is used. The simulation model of clutch-by-wire system is developed in the AMESim environments under the geometrical dimensions and driving mechanisms of the clutch-by-wire system, such as the rotation speed of the DC motor, the gear ratio of the reducer, the design parameters of the release fork, the coefficient of the clutch diaphragm spring, and so on. The results show that the theoretical analysis of the clutch-by-wire system for commercial vehicles using the AMESim software find out the driving characteristics of the clutch actuator, and predict the performance characteristics of the clutch-by-wire system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.694-699
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• 2005

This paper deals with a control technique of eliminating the transient vibration of a geared mechanical system. This technique is based on a model-based control with a rotational speed sensor in order to establish the damping effect at the driven machine part. A rotational speed sensor is installed in a driven gear, namely a bull gear. A control model is composed of a reduced-order mechanical part expressed as a transfer function between the rotational speed of the motor and that of the bull gear. This control model estimates a load speed after the rotational speed of the bull gear is acted on the transfer function. The difference between the estimated load speed and the motor speed is calculated dynamically and it is added to the velocity command to suppress the transient vibration generated at the load. This control technique is applied to a dies driving spindle of a form rolling machine. In this paper, the performance of this control method is examined by simulations. The settling time of the residual vibration generated at the loading inertia can be shortened down to about 1/2 of the uncompensated vibration level.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.210-215
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• 1997

Safety diagnosis on the driving system of electric train is performed using the vibration and noise signals of running railway train. Safety diagnosis is tried on the viewpoints of the appreciation of superannuation and the fault diagnosis of motor, reduction gear and boggie. The appreciation of superannuation is checked by the rms vibration levels of driving parts and the fault diagnosis is done by analyzing the frequencies of the vibration signals. The methods of measuring and analyzing the signals are decided on the basis of field 1-measured signals. The results shows that the vibration levels of each parts increase as the train goes older and each parts have their own frequency patterns of the vibration. As the results, the vibration and noise can be utilized successfully for the safety diagnosis of the driving part of electric train.

• Tribology and Lubricants
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• 제29권2호
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• pp.111-116
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• 2013

This paper describes the adherence phenomenon, including the tribological characteristics, of a low-pressure fuel pump in a diesel engine for an excavator. Most fuel pumps of a diesel-engine excavator are of the fixed-quantity-gear type and have low pressure. However, the developed pumps develop problems in the pumping system owing to performance instability. Cavitation, which is the main obstacle to stable driving in the pump, occurs between an idle gear and the housing to produce a serious adherence problem. The present study not only examined how to suppress cavitation in a pump but also developed a simple method to improve pump performance through the early creation of a lubrication film with a phosphoric acid coating on the surface of the idle gear. The results showed that the coating successfully prevents breakage of the idle gear due to adherence.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.34-39
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• 2013

The gear shifting timing of a manual transmission vehicle is influencing fuel economy. This paper focuses on an gear shifting indicator of an city bus with manual transmission, which can improve fuel economy. The shift indicator is supposed to collect the vehicle data during driving, calculate and compare fuel economy with and without gear shifting, and indicate the proper gear shifting timing. The H/W and S/W of the shift indicator are developed and tested on city bus in this research. The experiments are carried out on real road by 3 different drivers and the results show the improvement of fuel economy from 6.0% to 21.4%. The average engine torque and speed are reduced due to early gear shifting and the usage of highest gear is increased. The results of chassis test are also performed and show 7.5% improvement of fuel economy.