• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.236-243
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• 2007

Steering systems are classified as FWS(front-wheel steering), RWS(rear-wheel steering) and AWS(all-wheel steering) according to steering position. AWS is effective to reduce turning radius and platform length because all wheels are steered. Although various rear wheel control logics for AWS were developed, these are applied to four wheel steering cars. Therefore new control logics must be developed to apply articulated vehicles. In the present study, it is suggested how to control the real wheels based on the virtual rigid axles and also how to set it to minimize the turning radius.

• 한국생산제조학회지
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• 제8권1호
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• pp.150-157
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• 1999

In this study, the loader was completed that has 4-wheel gear driven drivetrain of study (Ⅰ), the 4-wheel steering with power wheel type, all-wheel traction system, and joy-stick type lever for hydraulic control valve. From driving test of the developed 4WD and 4WS type loader, we obtained that the minimum circling radius and the necessary width in circling motion reduced about 40% and 33% compared with 2WS type loader. Also, all-wheel traction system could keep the tires glued to the ground with greater stability, the power steering allowed a smoother operation, and the joy-stick type lever offered easily to control. Thus, the developed loader having these functions was very fit in a small cattle shed or rugged ground.

• 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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• 제3권3호
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• pp.66-78
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• 1995

In this paper, we address vehicle modeling and dynamic analysis of four wheel steering systems (4WS). 4WS is one of the devices used for the improvement of vehicle maneuverability and stability. All research done here is based on a production vehicle from a manufacturer. To study actual system response, a three dimensional, full vehicle model was created. In past research of this type, simple, two dimensional, bicycle vehicle models were typically used. First, we modelled and performed a dynamic analysis on a conventional two wheel steering(2WS) vehicle. The modeling and analysis for this model and subsequent 4WS vehicles were performed using ADAMS(Automatic Dynamic Analysis of Mechanical Systems) software. After the original vehicle model was verified with actual experiment results, the rear steering mechanism for the 4WS vehicle was modelled and the rear suspension was changed to McPherson-type forming a four wheel independent suspension system. Three different 4WS systems were analyzed. The first system applied a mechanical linkage between the front and rear steering mechanisms. The second and third systems used, simple control logic based on the speed and yaw rate of the vehicle. 4WS vehicle proved dynamic results through double lane change test.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.25-33
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• 2013

All-wheel steering (AWS) system is applied to articulated vehicles to reduce turning radius. The swing-out suppression algorithm is applied to AWS ECU, a key component of AWS system. The swing-out suppression algorithm applied to AWS ECU has a problem when velocity of vehicle is changed. In this paper, new algorithm based on moving distance that solve velocity problem is proposed. The HILS simulation and the test articulated bus is used to validate algorithm.

• 드라이브 ㆍ 컨트롤
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• 제14권2호
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• pp.30-36
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• 2017

This paper presents a sliding mode observer-based fault detection algorithm for steering inputs of an all-terrain crane. All-terrain cranes with multi-axles have several steering modes for various working purposes. Since steering angles at the other axles except the first wheel are controlled by using the information of steering angle at the first wheel, a reliable signal of the first axle's steering angle should be secured for the driving safety of cranes. For the fault detection of steering input signal, a simplified crane model-based sliding mode observer has been used. Using a sliding mode observer with an equivalent output injection signal that represents an actual fault signal, a fault signal in steering input was reconstructed. The road steering mode of the crane's steering system was used to conduct performance evaluations of a proposed algorithm, and an arbitrary fault signal was applied to the steering angle at the first wheel. Since the road steering mode has different steering strategies according to different speed intervals, performance evaluations were conducted based on the curved path scenario with various speed conditions. The design of algorithms and performance evaluations were conducted on Matlab/Simulink environment, and evaluation results reveal that the proposed algorithm is capable of detecting and reconstructing a fault signal reasonably well.

• 한국군사과학기술학회지
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• 제16권3호
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• pp.240-249
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• 2013

This paper discusses the maneuvering control algorithm based on all-wheel independent driving and steering control techniques for special purpose 6WD/WS vehicles. The maneuvering control algorithms considering superior dynamic characteristics of high power in-wheel motors and independent steering system are designed to perform driving, steering, vehicle stability, and fault tolerant control. The maneuvering controller applies sliding and optimal control theories considering optimal torque distribution and friction circle related to the vertical tire force. The fault tolerant control algorithm is applied to obtain the similar maneuverability to that of the non-faulty vehicle. The simulations using the Matlab/Simulink dynamics model and experiments using HIL simulator mounting the real controllers with the designed control algorithms prove the improved performances in terms of vehicle stability and maneuverability.

• 정보처리학회논문지A
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• 제17A권1호
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• pp.19-26
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• 2010

삶의 질이 높아지고 고령화 사회가 시작되면서, 사회적 약자들이 사용하기 쉬운 교통수단의 개발의 필요성이 증대되고 있다. 이러한 요구에 부응하기 위해, 한국철도기술연구원에서 주관하여 저상굴절버스(Bi-modal Tram)의 개발을 시작하게 되었다. 이 저상굴절버스는 버스와 같은 높은 접근성의 특징을 가져야 할 뿐만 아니라, 지하철과 같이 차체가 낮아야 하며, 휠체어나 승객의 발이 승강장과 차량 사이 틈에 끼지 않도록 정확한 주차가 이루어져야 한다. 하지만 저상굴절차량의 길이가 길어, 이러한 요건을 맞추기 위해서는 전 차륜 조향 시스템이 개발-장착되어야 한다. 전 차륜 조향 시스템이 장착된 저상굴절차량은 1축 차륜이 조향될 뿐 아니라, 1축 조향각 또는 굴절각과 속도 등의 상태에 따라 2축과 3축 차륜이 조향되는 특징을 가지고 있다. 본 연구에서는 전 차륜 조향장치의 개발 과정을 다룬다.

• 한국생산제조학회지
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• 제7권6호
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• pp.141-148
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• 1998

A loader is construction & road or agricultural machinery for lifting, moving, and mixing. This study deals with the agricultural mini loader for stock raising farming. The performance of the machine is established by pulling power, working lifting capacity, and minimum circling radius, etc. Also, driving easiness and endurance are very important in manufacturing. Thus, this study has developed the loader with the 4-wheel driving equipment by gear transmission, the 4-wheel steering equipment by power handle steering type, and the equipment making four wheels touch simultaneously on the rugged ground. The developed loader having these functions was very fit in a small cattle shed or a rugged ground. This study is divided into two parts; (I) development of 4WS transmission and (II) construction of the loader by 4WS system and other equipments.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1616-1625
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• 2007

Recently, embedded systems role as control systems instead of mechanical control systems in many parts of vehicles. In cases that embedded systems are used controling the electric signal, it is important to secure the reliability of a software within embedded systems. In this paper, the test platform for securing the reliability and real-time characteristic of the embedded system that controls electric signal of All Wheel Steering Control System in a Bi-modal tram is proposed. The platform is built on a HIL (Hardware In the Loop) architecture. Through the HIL platform, various vehicle conditions, driver activities and environment conditions can be successfully tested without actual driving, hence improving the reliability of the embedded system for the All Wheel Steering Control System.