• 한국자동차공학회논문집
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• 제13권2호
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• pp.37-43
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• 2005

A haptic steering system which reflects steering reaction torque has been developed for a fixed base vehicle simulator. The haptic steering system consists of a steering effort sensor, MR-clutch, AC servo motor and controller. In order to generate realistic steering torque feel to driver and at the same time to meet real-time simulation requirement, 3D torque map is constructed by experimental data and torque generation algorithm using the torque map has been also developed. 3D torque map is constructed using curve fitting and interpolation of the measured values of the steering angle, velocity and steering torque from actual slalom test on the proving ground. In order to carry out performance test of the developed haptic steering system, a fixed based vehicle simulator is constructed by integrating real time vehicle dynamics module, VR-video/audio module, and the haptic steering system. Steering torque and steering angle curves have been obtained from virtual testing in the vehicle simulator and performance of the haptic steering system has been evaluated.

• 대한기계학회논문집A
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• 제41권2호
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• pp.111-119
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• 2017

본 논문은 자세 제어 장치(ESC)와 후륜 조향 장치(RWS)를 장착한 통합 섀시 제어기의 성능을 향상시키기 위해 후륜 조향각을 결정하는 방법을 제안한다. 차량을 안정화시키기 위해 필요한 제어 요 모멘트는 자세 제어 장치와 후륜 조향 장치를 이용하여 만들어진다. 각 장치의 타이어 힘을 결정하기 위해 의사역행렬 제어할당 방법을 적용한다. 제어기의 성능을 향상시키기 위해 후륜 조향 장치의 조향각을 결정하는 데에 네 가지 방법을 적용한다. 차량 시뮬레이션 패키지인 CarSim에서 시뮬레이션을 수행하여 제안된 방법들이 통합 섀시 제어기의 성능을 향상시킬 수 있음을 검증한다.

• 한국진공학회지
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• 제15권4호
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• pp.410-420
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• 2006

Epitaxial 성장에서 screening 및 steering 효과 등과 같은 증착과정 중 나타나는 dynamic effects를 kinetic Monte Carlo 시뮬레이션으로 고찰하였다. 증착원자와 토대 원자와의 상호 작용을 엄밀하게 고려하기 위해 이 시뮬레이션 프로그램에 molecular dynamics 시뮬레이션을 결합시켰다. 기울어진 각도로 증착 시킬 경우 표면의 형상은 1) 증착 각도가 기울어짐에 따라 거칠기가 증가한다는 것, 2) 비대칭적인 언덕의 형성된다는 것, 그리고 3) 언덕의 면방향에 따라 비대칭적인 기울기를 갖는다는 세가지 특징을 보았다. 증착 각도나 온도 의존성에 대한 시뮬레이션 결과는 기존의 실험 결과와 잘 일치하는 것을 확인하였다. 기울어진 각도로 증착했을 때 나타나는 이러한 결과는 steering과 screening 효과에 따른 초기 증착 밀도의 불균일에 기인함을 알 수 있었고, 여기서 steering 효과가 screening 효과 보다 주요한 역할을 하는 것을 보았다. 시뮬레이션 계산에서 확인된 새로운 결과는 기울기 선택 (slope selection)이 이루어졌어도 언덕의 각 면이 단일한 기울기로 형성되어 있지 않고 여러 종류의 facet가 섞인 형태이며, 따라서 기울기 선택이 바로 facet 선택을 의미하지는 않는다는 것이다.

• 드라이브 ㆍ 컨트롤
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• 제12권3호
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• pp.36-43
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• 2015

An autonomous vehicle control algorithm based on Ackerman Geometry is known to be reliable in low tire slip situation. However, vehicles at high speed make lateral errors due to high tire slip. In this paper, considering the tire slip of vehicles, the steering angle is determined based on the Ackerman Geometry and is supplemented tire slip angle by the Stanley steering algorithm. In addition, to prevent the tire slip, the algorithm, which restricts steering if a certain level of slip occurs, is used to reduce the lateral error. While many studies have been extended to include vehicle slip, studies also need to be carried out on the tire slip depending on hardware performance. The control algorithm of autonomous vehicles is compensated considering the sensor noise and the performance of steering actuator. Through the various simulations, it was found that the performance of steering actuator was the key factor affecting the performance of autonomous driving. Also, it was verified that the usefulness of steering algorithm considering the tire slip and performance of steering actuator.

• 제어로봇시스템학회논문지
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• 제19권1호
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• pp.45-55
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• 2013

With the recent advancement of control method and battery technology, the electric vehicle have been researched to replace the conventional vehicle with electric vehicle with the view point of the environmental concerns and energy conservation. An electric vehicle which is equipped with the independent front steering system and in-wheel motors has advantage in terms of control. For example, the different torque which generated by left and right wheels directly can make yaw moment and the independent steering using outer wheel control is able to reduce the sideslip angle. Using of independent steering and driving system, the 4 wheel electric vehicle can improve a performance better than conventional vehicle. In this paper, we consider the method for improving the cornering performance of independent front steering system and in-wheel motor used electric vehicle with the compensated outer wheel angle and direct yaw moment control. Simulation results show that the method can improve the cornering performance of 4 wheel electric vehicle. We also apply the steering motor failure to steer the vehicle turned by the torque difference without steering. This paper describes an independent front steering and driving, consist of three parts; Vehicle Model, Control Algorithm for independent steering and driving and simulation. First, vehicle model is application of TruckSim software for independent front steering and 4 wheel driving. Second, control algorithm describes the reduced sideslip and direct yaw moment method in view of cornering performance. Last is simulation and verification.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1541-1542
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• 2011

• 전자공학회논문지 IE
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• 제49권2호
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• pp.30-39
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• 2012

졸음운전은 사고발생 확률이 높고, 사고 발생 시 심각도가 높기 때문에 효율적인 졸음운전 판단 시스템이 필요하다. 그러나 생체 신호나 비전을 이용한 졸음운전 판단시스템은 비용 측면에서 활용되기가 어렵다. 이에 본 논문에서는 추가적인 비용 없이 대부분의 차량에 기본 장착되어 있는 조향각 센서(steering angle sensor)와 차량정보(brake switch, throttle position signal, vehicle speed)를 이용하여 졸음운전자의 조향패턴 중 하나인 저킹 판단을 이용한 졸음운전 판단 알고리즘을 제안한다. 본 연구에서는 각 변수의 임계값을 제시하고, HILS(Hardware in the Loop Simulation)에서 CAN을 통해 취득한 차량의 데이터와 Matlab 프로그램을 이용하여 알고리즘을 평가한다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권2호
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• pp.182-186
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• 2004

This paper describes an advanced compensation for non-linear functions designed to remove steering aberrations from phased array antennas. This system alters the steering command applied to the antenna in a way that the appropriate angle commands are given to the array steering software for the antenna to point to the desired position instead of squinting. Artificial neural networks are used to develop the inverse function necessary to correct the aberration. Also a straightforward antenna steering function is implemented with neural networks for the 9-term polynomials of forward steering function. In all cases the aberration is removed resulting in small RMS angular errors across the operational angle space when the actual antenna position is compared with the desired position. The use of neural network model provides a method of producing a non-linear system that can correct antenna performance and demonstrates the feasibility of generating an inverse steering algorithm.

• 한국항만학회지
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• 제13권2호
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• pp.381-388
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• 1999

To improve the productivity in the harbor, successful development of an UCT(Unmanned Container Transporter) is needed. Well-designed steering and velocity control systems are the key factor for the development of the UCT. In this paper, a research concerning the achievement of the steering control is introduced. To get an information on the guide line that the UCT should track, the vision system is applied. By using neural network, proper steering angle is gotten fast with less influence of the image disturbance. A simulation based on the UCT kinematics is performed with the measured steering angle, and it shows satisfactory results.

• 대한인간공학회지
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• 제30권2호
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• pp.285-290
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• 2011

Due to the ageing-related degradation in physical and cognitive abilities, the elderly have difficulty in car driving and this is related to the high rate of car accidents among them. This study investigated the kinematic characteristics of old drivers' steering in right turning at intersections by comparing with young drivers. Thirteen old(60~70) and thirteen young(20~30) drivers who participated in the experiment turned their cars right side at intersections in a driving simulator. As results, the completion time of right turning at intersection of old drivers was larger than that of young drivers. The speeds of vehicle at the beginning and ending point of the right turning area of old drivers were smaller than those of young drivers, and also the steering angle at the ending point of the turning area of the former was smaller than that of the latter. The normalized jerk of old driver's steering was significantly larger than that of young drivers. These results indicate that old drivers modify their steering movement repeatedly and take the driving strategy of avoiding risks due to their reduced physical capabilities.