• 대한기계학회논문집A
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• 제37권6호
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• pp.731-738
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• 2013

본 논문은 6 륜 독립구동/독립조향 차량의 독립 스티어-바이-와이어 장치의 고장 안전 주행 제어방법을 제시하였다. 조향부 고장 휠의 횡방향 타이어 힘이 차량 선회 운동에 저항력으로 작용할 수 있으므로, 이를 줄이기 위하여 본 고장 안전 주행 제어 알고리즘은 조향부 고장 휠에 높은 슬립률이 발생하도록 토크 입력을 가한다. 고슬립으로 인한 조향부 고장 휠의 종방향 타이어 힘 증가를 고려하기 위하여 종방향 타이어 힘을 추정하여 고장나지 않은 휠의 구동력 최적 분배에 구속 조건에 포함시킨다. 개루프 조향 및 폐루프 조향 시뮬레이션 결과 조향부 고장이 발생한 차량의 주행시 고장을 고려하지 않은 최적 구동력 분배 제어에 비하여 본 알고리즘 적용시 차량의 주행 성능이 보정됨을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.347-349
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• 1998

This paper describes a fuzzy identification model for slip - adhesion curve of High - speed trains. The model has fuzzy inputs corresponding to rail condition and crisp inputs for train. Nonlinear function is obtained by using fuzzy outputs. Finally slip - adhesion curve is given by the function. First, Results are presented of slip - adhesion curves under the influence of changing rail condition. Second, Dynamic moving simulation by proposed fuzzy slip - adhesion model is presented. Simulation results show fine characteristics.

• 대한조선학회논문집
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• 제50권6호
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• pp.407-413
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• 2013

In the conventional towing tank, the ordinary towing carriage has a speed barrier which caused not only by the limitation of the length of towing tank but also the limitation of acceleration. Therefore the length of the towing tank should be decided carefully from the planning stage of the towing tank construction. Consequently the acceleration of the towing carriage should be taken less than 0.06g practically to avoid the slip of the wheel on rail. Due to the increasing demand of the high speed experiments on the development of special novel ship, the requirement of the high speed towing carriage is continuously increased recently. When the minimum measuring time of the towing experiment is prescribed as five seconds, the carriage should be accelerated with higher than 0.12 g to get the speed of 18 m/sec even in the towing tank having a length of 400m in length approximately. This means that the requirement of acceleration is bigger than twice of the ordinary practices of carriage acceleration. In such a condition the exerted total power of motor could not converted to traction force for the acceleration of the carriage without slip. To over come these difficulties a pair of horizontal traction wheels are reinforced to each of the ordinary vertical carrier wheel and appropriate suspension system has been devised for the towing tank of super high speed operation. It is believed that the design of novel suspension system adaptable for the high speed acceleration of towing carriage will play a important role as a reference for the remodeling of the towing tank for high speed experiment.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.311-312
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• 2006

In this paper, steering systems for mobile robot with permanent magnet wheels are discussed. The mobile robot with permanent magnet wheels can have three different types of steering and driving configurations; two-wheels, three-wheels, four-wheels. By a Two-WD(Wheel Driving) system, driving and steering characteristics are controlled by ratio of each wheel speeds. Three-WD system is steered by a front wheel and driven by rear wheels. Four-WD system has better stability than two wheel system. Usually the permanent magnet wheel has nearly none slip. Thus turning radius of the mobile robot with three-WD and four-WD System will be increased and the steering and driving system will be complicated. To solve this problem, two magnet wheels with two dummy wheels are used in this study. fuming radius of the developed mobile robot is small and the structure of the robot is simple. It is possible to move forward, backward, to turn left and right, and to rotate freely with two-WD. This study proved that two-WD system is very suitable fur the mobile robot with permanent magnet wheels.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.61-64
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• 2006

This paper presents experimental analysis of a friction-driven wheel responsible for generating wheel squeal. Squeal noise generating mechanism has been examined under the laboratory condition by the model rig. Creep characteristics and squeal noise were observed by varying relative velocity of the wheel with respect to the rail and friction coefficient. Computational radiating noise analysis was also performed based on the modal analysis and noise transfer function measurement of the object wheel.

• 대한토목학회논문집
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• 제37권4호
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• pp.693-703
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• 2017

달 탐사 로버 휠의 주행 성능은 지반 조건과 휠의 형상에 따라 크게 달라진다. 이에 본 연구에서는 한국형 인공월면토 및 주문진 표준사에서 휠 형상을 변화시켜 달 탐사 로버 휠의 주행성능 평가를 실시하였다. 단일 휠 성능평가 실험장비를 이용하여 지반조건에 따른 영향을 검토하였고, 이와 더불어 인공월면토에서 그라우저 높이에 따른 휠 주행성능 평가를 실시하였다. 휠 주행성능 평가는 슬립율에 따른 토크, 견인력 및 침하량을 측정하여 각 조건별로 상대적인 비교를 하였다. 실험 결과 주문진 표준사에 비해 한국형 인공월면토에서 로버 휠 주행성능이 우수하였으며, 휠 주행성능이 흙의 점착력과 마찰각 특성에 큰 영향을 받는 것으로 나타났다. 또한, 휠 그라우저 높이에 따라 견인성능이 증가하는 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2569-2571
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• 2000

In the vehicle steering system, we can consider two methods to steer the vehicle. One is a front wheel steering(FWS), the other is a four wheel steering(4WS). The four wheel steering method has been recently introduced to improve the steering performance. In this paper, we present a design of the four wheel steering controller. First, we constructed the neural network two degree of freedom PID controller to control the 4WS system. Then we compared the performance of conventional PID controller with our proposed controller in terms of yaw rate and side slip velocity. The computer simulation results show that 4WS system controlled by the proposed controller has well driving performances than the other.

• 한국지반공학회논문집
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• 제32권11호
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• pp.97-108
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• 2016

달 탐사시 탐사 로버는 반드시 필요하며, 특히 월면토와 로버 휠의 상호작용에 의한 로버 휠의 성능은 로버의 최적 형상을 결정하는데 있어서 매우 중요하다. 본 연구에서는 한국형 인공 월면토(KLS-1)에서 달 탐사 로버 휠의 거동 성능을 평가하기 위하여 단일 휠 성능평가 실험장비를 개발하였고, 이를 이용하여 그라우져 유무에 따른 휠 성능 평가 실험을 수행하였다. 휠 성능은 슬립율에 따른 견인력, 토크, 침하 등으로 평가하였으며, 실험 결과 개발된 단일 휠 성능평가 실험장비는 휠 성능을 적절히 평가하는 것으로 나타났으며, 한국형 인공 월면토에서 그라우져가 있는 휠이 그라우져가 없는 휠에 비해 높은 견인 성능을 보여주었다. 향후 본 실험은 한국형 로버의 최적 휠 결정을 위해 사용될 수 있을 것으로 판단된다.

• Journal of Mechanical Science and Technology
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• 제14권8호
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• pp.836-844
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• 2000

In this research any abnormal motion of a vehicle is detected by utilizing the difference between the reference and actual yaw velocities as sell as the information on vehicle slip angle and slip angular velocity. This information is then used as a criterion for execution of the yaw moment control. A yaw moment control algorithm based on the brake control is proposed for improving the directional stability of the vehicle. The controller executes brake controls to provide each wheel with adequate brake pressures, which generate the needed yaw moment. It is shown that the proposed yaw moment control logic can provide excellent cornering capabilities even on low friction roads. This active control scheme can prevent a vehicle from behaving abnormally, and can assist normal drivers in coping with dangerous situations as well as experienced drivers.

• 대한기계학회논문집A
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• 제22권2호
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• pp.428-436
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• 1998

A TCS slip control system improves acceleration capability and steerability on slippery roads through engine torgue and/or brake torque control. This research mainly deals with the engine control algorithm via the adjustment of the engine throttle angle. The following new control strategy is proposed and investigated ; the TCS slip controller whose input is the difference between the desired driving wheel speed corresponding to the optimum slip ratio and the actual speed yields the target engine torque and then estimates the throttle angle based on the engine performance curve. Various simulation and hardware-in-the-loop simulation have been carried out. The results show the proposed strategy may compensate for the inherent nonlinearity between variation of the throttle angle and variation of the engine torque and produce better performance than the previous strategies without the engine map, especially in the high speed region.