• 한국자동차공학회논문집
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• 제25권2호
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• pp.167-178
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• 2017

The steering wheel of a vehicle has a typical characteristic of automatically returning to its neutral state when the driver releases it. Steering returnability originated from the tire forces and kingpin moments. It is proportional to the reaction torque that is generated through the rack and column, which are dependent on suspension and steering geometry. It is also important to accurately predict and design it because steering returnability is related to steering performance. In this study, a detailed multibody dynamics model of a vehicle was designed by using ADAMS/Car and simulated for steering returnability. In addition, a tolerance analysis of the chassis system in terms of part dimension and properties has been performed in order to minimize the design parameters. The sensitivity of the selected design parameters was then analyzed via Design of Experiments(DOE). As a result, we were able to obtain the main parameters through a contribution analysis. It can be used to predict steering returnability and improve its performance, which is represented by the angle of restoration and laterality.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.69-76
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• 2004

This paper evaluates the effectiveness of four-wheel-steering system from the viewpoint of lane-keeping control theory. In this paper, the lane-keeping control system is designed on the basis of the four-wheel-steering automobiles whose desired steering response is realized with the application of model matching control. Two types of desired steering responses are presented in this paper. One is zero-sideslip response, the other one is steering response which realizes zero-phase-delay of lateral acceleration. Using simplified linear two degree-of-freedom bicycle model, simulation study and theoretical analysis are conducted to evaluate the lane-keeping control performance of active four-wheel-steering automobiles which have different desired steering responses. Finally, the evaluation is conducted on straight and curved roadway tracking maneuvers.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.257-257
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• 2000

The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A predictive control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in forward and backward direction in such a way to satisfy the given constraint condition, maintain consistency, reduce the uncertainties, and guarantee robustness. A series of experiments was conducted to evaluate the control performance, in which a car Like robot was utilized to quit unwanted safety problem. As the results, the robot was keeping very well a given lane with arbitrary shape at moderate speed.

• 한국해양공학회지
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• 제27권6호
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• pp.81-89
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• 2013

This paper considers the steering characteristics of a four-row tracked vehicle crawling on extremely cohesive soft soil, where each side is composed of two parallel tracks. The four-row tracked vehicle (FRTV) is assumed to be a rigid body with 6-DOF. A dynamic analysis program for the tracked vehicle is developed using the Newmark-${\beta}$ method based on an incremental-iterative scheme. A terra-mechanics model of an extremely cohesive soft soil is implemented in the form of the relationships of the normal pressure to the sinkage, the shear resistance to the shear displacement, and the dynamic sinkage to the shear displacement. In order to investigate the steering characteristics of the four-row tracked vehicle, a series of dynamic simulations is conducted with respect to the distance between the left and right tracks (pitch), steering ratios, driving velocity, reference track velocity, lengths of the tracks, and properties of the cohesive soft soil. Through these numerical simulations, the possibility of using a kinematic steering ratio is explored.

• 한국지능시스템학회논문지
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• 제22권5호
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• pp.597-602
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• 2012

본 논문에서는 유인과 무인주행이 가능한 전기자동차용 수동 및 자동 조향장치를 제안한다. 기존의 엔진방식의 자동차에 사용되는 자동 조향시스템인 EPS, MDPS는 주행 중에 과부하시엔 핸들 잠김 현상이 발생하는 문제점이 있어 유무인 전기자동차에 적용하는 것은 한계가 있다. 제안하는 수동 및 자동 조향장치는 전자클러치와 풀리를 이용함으로써 수동과 자동변환이 가능하도록 조향 메커니즘을 설계하였다. 제안한 조향장치의 성능을 실험하기 위해 실험용 전기자동차를 제작하고 조향성능을 실험하였다. 실험을 통해 제안하는 수동 및 자동 조향장치는 유무인 전기자동차에 유용함을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1874-1879
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• 2004

This paper validates new type electric power steering (EPS) system which is driven by a uni-direction rotational motor and two electromagnetic clutches. The assist motor of the new type EPS produces a torque for assisting the steering in only one direction and two electromagnetic clutches transmit the assist torque to the pinion gear in either left or right direction with respect to the steering rotation. In order to evaluate the static and dynamic characteristics of the new type EPS, the EPS has been modeled by using the well known customized software such as MSC.ADAMS and MSC.CarSim. The ADAMS software has been used to investigate the static characteristics of the proposed system. ADAMS, however, can not describe dynamics of a vehicle and perform the simulation under the various road conditions. Thus the dynamic characteristics of the vehicle including the EPS are analyzed very well by using the CarSim software. A sinusoidal steering input command is applied to the propose EPS system in order to evaluate the static characteristics, while the double lane changes are applied to the vehicle with the EPS in order to evaluate the dynamic performance. Through a series of simulations, we can conclude that the propose EPS shows the stable dynamic characteristics when the rotational direction is changed.

• 한국자동차공학회논문집
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• 제22권6호
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• pp.59-67
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• 2014

A numerical model and a controller of Active Front wheel Steer (AFS) system are designed in this study. The AFS model consists of four sub models, and the AFS controller uses sliding mode control and PID control methods. To test this model and controller an Integrated Dynamics Control with Steering (IDCS) system is also designed. The IDCS system integrates an AFS system and an ARS (Active Rear wheel Steering) system. The AFS controller and IDCS controller are compared under several driving and road conditions. An 8 degree of freedom vehicle model is also employed to test the controllers. The results show that the model of AFS system shows good kinematic steering assistance function. Steering ratio varies depends on vehicle velocity between 12 and 24. Kinematic stabilization function also shows good performance because yaw rate of AFS vehicle tracks the reference yaw rate. IDCS shows improved responses compared to AFS because body side slip angle is also reduced. This result also proves that AFS system shows satisfactory result when it is integrated with another chassis system. On a split-m road, two controllers forced the vehicle to proceed straight ahead.

• 한국정보통신학회논문지
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• 제13권11호
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• pp.2289-2294
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• 2009

이 논문에서는 라인 트레이스 차량의 주행 제어를 위한 퍼지 제어기를 설계하였다. 라인을 감지하는 센서들의 감지 상태에 따라 센서값을 산출하고 이 센서값은 조향각 제어 퍼지 추론 규칙의 입력으로 사용되어 조향각을 제어값으로 산출한다. 또한 산출된 조향각은 다시 모터속력 제어 추론 퍼지 규칙의 입력으로 사용되어 주행 속도 결정을 위한 모터속력을 제어값으로 산출하게 된다. 제안한 퍼지 제어 기법을 이용하여 조향각만을 제어한 경우와 조향각과 모터속력을 함께 제어한 경우를 각각 실험한 결과, 모터속력을 함께 제어한 경우가 트랙을 이탈하지 않으면서 더욱 빠르게 주행하여 제안한 기법에 더욱 효과적임을 알 수 있었다.

• 한국정밀공학회지
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• 제29권7호
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• pp.745-752
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• 2012

The pivot steering of an individual wheel motor drive vehicle is an effective steering maneuver in the narrow road, but it has become a matter of concern that the torque input of each wheel is very difficult to determine. In this study, the independent yaw moment control was proposed for the smooth pivot steering control of an in-wheel drive vehicle. For this control method, the vertical forces of tires were estimated from the trailing arm dynamic model, and the yaw moments of individual wheels were calculated from the vehicle dynamic model. Dynamic simulation results showed that the independent yaw moment control was much more effective on the minimization of the instabilities of pivot steering in comparison with the conventional direct yaw moment control with yaw rate feedback.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.160.3-160
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• 2001

The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A new control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in ...