• 한국항해학회지
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• 제22권1호
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• pp.79-89
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• 1998

When an automatic course-keeping is concerned , as is quite popular in modern navigation, the closed-loop steering system consists of autopilot device, power unit(or telemotor unit), steering gear, magnetic or gyro compass and ship dynamics. In order to estimate steering system of ship in open seas, we need to know the characteristics of each component of the system and also to know the characteristics of disturbance to ship dynamics. Calculation methods of irrgular disturbances are based on the linear superposition principle. In this paper, for the purpose of evaluation of automatic steering of ships , the influences of linear control constants of autopilot on propulsive energy loss are investigated bya performance index is introduced from the viewpoint of energy saving. Numberical calculations are carried out for an are carrier and for a fishing boat in multi-directional waves.

• 한국기계가공학회지
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• 제11권1호
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• pp.68-75
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• 2012

In this study, the optimal synthesis of planar steering mechanisms for vehicles is studied. The author minimized the steering error between two front wheels subject to the constraints of transmission angles. Nonlinear programming methods such as BFGS method and golden section search method are used for this optimization. As numerical examples, Ackermann's steering mechanism, 6-link and 10-link planar mechanism are adopted to check the usefulness of this method. Consequently, among the three optimized mechanisms, 10-link planar one conducts far more accurate performance subject to tight constraints of transmission angles.

• 한국정밀공학회지
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• 제19권10호
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• pp.178-186
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• 2002

In this study, the steering control system for UCT (unmanned container transporter) was developed using MR (Magnetoresistive) sensors. The MR and magnet sensors are used for the lane detecting system. The robust control theory is used for the design of the steering controller to reduce the uncertainties of the road. The performance of the robust steering controller is compared in simulations and tests using the existing PD controller of the UCT.

• 대한기계학회논문집A
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• 제29권6호
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• pp.809-814
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• 2005

The goal of this paper is to minimize the weight of the T-structure supporting steering system in reducing the vibration level on steering wheel which could be amplified by the resonance. Presently, requirements for reducing noise, vibration and harshness (NVH) in automotive area are more stringent than ever. One of them is the vibration of steering system which occurs sometimes at high speeds or when the engine is idling. Besides, the reduction of weight is also one of requirements for improvement of vehicle performance. This paper used the micro genetic algorithm as an optimization method to satisfy above two requirements. The whole T-structure assembly including steering column was used for frequency analysis.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.15-20
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• 2012

This study is to propose and develop an integrated dynamics control system to improve and enhance the lateral stability and handling performance. To achieve this target, we integrate an AFS and a 4WS systems with a fuzzy logic controller. The IDCS determines active additional steering angle of front wheel and controls the steering angle of rear wheel. The results show that the IDCS improves the lateral stability and controllability on dry asphalt and snow paved road when double lane change and step steering inputs are applied. Yaw rate of the IDCS vehicle tracks reference yaw rate very well and body slip angle is reduced about by 50%. Response time of the IDCS vehicle is also decreased.

• 한국철도학회논문집
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• 제4권1호
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• pp.1-8
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• 2001

In this paper, the dynamics and stability of the automated guideway transit (AGT) vehicles with rubber tires are investigated. Two types of AGT systems are considered: the bogie-type and steering-type systems. The critical speeds for the dynamic instability of lateral and yawing motions are investigated by use of the Routh-Hurwitz's stability criterion. It is shown that the bogie-type AGT vehicles are likely to be stable within the range of practical operating speed, whereas it is not true for the steering-type AGT vehicles. It is also shown that the control performance of steering-type AGT vehicles can be improved by choosing proper steering gains of the closed-loop steering control system.

• 한국지능시스템학회논문지
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• 제9권5호
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• pp.480-489
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• 1999

Design and experimental results of yaw rate controller is described for electricallydriven four wheel vehicle without steering mechanism. Yaw rate controller has been known to be necessary to cope with nonlinear char-acteristics of the wheel/road conditions with respect to different road condition and steering angle. For an effective yaw rate control, a fuzzy PID gain scheduler is considered with changing control parameters. In order to apply proposed algorithm to the system a downsized four wheel drive electrically driven vehicle without steering mechanism was manufactured. With these techniques the proposed yaw rate controller is shown by experiment results to be obtained suficient performance in the whole steering regions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2386-2389
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• 2001

This paper describes neural network steering controller for an AGV using MR sensor. The analytical magnetic fields model was compared with measured data and found to have less than 1 % difference. The neural network was also used to learn the steering behaviour of the AGV relative to the magnetic field values(Bx, By, Bz). A computer simulation of the AGV (including AGV's dynamics and steering) was used to verify the steering performance of the controller using the neural network. Good results were obtained. Also, the handmade AGV using neural network controller verified good results.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.189-195
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• 2003

The steel wheels are widely used in the passenger cars because of their low cost of production although the aluminum wheels have many advantages in their performance and appearance. It is known that the steering wheel vibration with steel wheels is generated more often than one with aluminum wheels. Both the constant velocity driving test and the m up test are carried out in this study to analyze the causes and path of the steering wheel vibration generated from the steel wheels. And this study shows that the steering wheel vibration is affected by the fastening torque of the wheel mounting bolts between the steel wheel and the suspension disk.

• 자동차안전학회지
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• 제15권2호
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• pp.13-20
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• 2023

This paper presents a fault tolerant control strategy for Steer-by-Wire (SbW) systems. Among many problems to be solved before commercialization of SbW systems, maintaining reliability and fault tolerance in such systems are the most pressing issues. In most previous studies, dual steering motors are used to achieve actuation redundancy. However, relatively few studies have been conducted to introduce fault tolerant control strategies using rear wheel steering system. In this work, an actuator fault in front wheel steering is compensated by active rear wheel steering. The proposed fault tolerant control algorithm consists of disturbance observer and sliding mode control. The fault tolerant control performance of the proposed approach is validated via computer simulation studies with Carsim vehicle dynamics software and MATLAB/Simulink.