• Title, Summary, Keyword: Vehicle Model

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Vehicle Steering Characteristics Simulation by a Driver Model (운전자 모델을 사용한 차량의 조향특성 시뮬레이션)

  • Lee, J.S.;Baek, W.K.
    • Journal of Power System Engineering
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    • v.7 no.3
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    • pp.61-68
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    • 2003
  • Steering characteristics is an important factor in the evaluation of vehicle quality. To estimate steering characteristics in the vehicle conceptual design stage, vehicle dynamics simulation methods are very efficient. However, it is often difficult to simulate vehicle dynamics for the specific driving scenarios in open-loop driving environment. An efficient driver-in-the-loop vehicle model will be efficient for this job. A good tire model is also very important for the accurate vehicle dynamics simulation. In this research, a driver model is used to simulate vehicle steering dynamics for a 8-dof vehicle model with STI(Systems Technology, Inc.) tire model. For the demonstration of this model, a SUV(sports utility vehicle) and a sedan were simulated.

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Wind loads on a moving vehicle-bridge deck system by wind-tunnel model test

  • Li, Yongle;Hu, Peng;Xu, You-Lin;Zhang, Mingjin;Liao, Haili
    • Wind and Structures
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    • v.19 no.2
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    • pp.145-167
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    • 2014
  • Wind-vehicle-bridge (WVB) interaction can be regarded as a coupled vibration system. Aerodynamic forces and moment on vehicles and bridge decks play an important role in the vibration analysis of the coupled WVB system. High-speed vehicle motion has certain effects on the aerodynamic characteristics of a vehicle-bridge system under crosswinds, but it is not taken into account in most previous studies. In this study, a new testing system with a moving vehicle model was developed to directly measure the aerodynamic forces and moment on the vehicle and bridge deck when the vehicle model moved on the bridge deck under crosswinds in a large wind tunnel. The testing system, with a total length of 18.0 m, consisted of three main parts: vehicle-bridge model system, motion system and signal measuring system. The wind speed, vehicle speed, test objects and relative position of the vehicle to the bridge deck could be easily altered for different test cases. The aerodynamic forces and moment on the moving vehicle and bridge deck were measured utilizing the new testing system. The effects of the vehicle speed, wind yaw angle, rail track position and vehicle type on the aerodynamic characteristics of the vehicle and bridge deck were investigated. In addition, a data processing method was proposed according to the characteristics of the dynamic testing signals to determine the variations of aerodynamic forces and moment on the moving vehicle and bridge deck. Three-car and single-car models were employed as the moving rail vehicle model and road vehicle model, respectively. The results indicate that the drag and lift coefficients of the vehicle tend to increase with the increase of the vehicle speed and the decrease of the resultant wind yaw angle and that the vehicle speed has more significant effect on the aerodynamic coefficients of the single-car model than on those of the three-car model. This study also reveals that the aerodynamic coefficients of the vehicle and bridge deck are strongly influenced by the rail track positions, while the aerodynamic coefficients of the bridge deck are insensitive to the vehicle speed or resultant wind yaw angle.

An Effect of the Complexity in Vehicle Dynamic Models on the Analysis of Vehicle Dynamic Behaviors: Model Comparison and Validation (차량 모델의 복잡성이 차량동력학 해석에 미치는 영향 : 모델의 비교 및 검증)

  • 배상우;윤중락;이장무;탁태오
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.6
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    • pp.267-278
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    • 2000
  • Vehicle dynamic models in handing and stability analysis are divided into three groups: bicycle model, roll axis model and full vehicle model. Bicycle model is a simple linear model, which hag two wheels with load transfer being ignored. Roll axis model treats left and right wheels independently. In this model, load transfer has a great effect on nonlinearity of tire model. Effects of suspension system can be analyzed by using full vehicle model, which is included suspension stroke motions. In this paper, these models are validated and compared through comparison with road test, and the effects of suspension kinematics and compliance characteristics on vehicle motion are analyzed. In handling and stability analysis, roll axis model can simulate the real vehicle motion more accurately than full vehicle model. Compliance steer has a significant effect, but the effect of suspension kinematics is negligible.

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Validation of a Vehicle Model and an ABS Controller with a Commercial Software Program (상용 소프트웨어를 이용한 차량 모델 및 ABS 제어기의 성능 평가)

  • Song, Jeong-Hoon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.5
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    • pp.180-187
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    • 2007
  • This paper presents a mathematical vehicle model that is designed to analyze the dynamic performance and to develop various safety control systems. Wheel slip controllers for ABS is also formulated to improve the vehicle response and to increase the safety on slippery road. Validation of the model and controller is performed by comparison with a commercial software package, CarSim. The result shows that performances of developed vehicle model are in good accordance with those of the CarSim on various driving conditions. Developed ABS controller is applied to the vehicle model and CarSim model, and it achieves good control performance. ABS controller improves lateral stability as well as longitudinal one when a vehicle is in turning maneuver on slippery road. A driver model is also designed to control steer angle of the vehicle model. It also shows good performance because the vehicle tracks the desired lane very well.

Validation of Driver Steering Model with Vehicle Test (실차 실험을 통한 운전자 조향 모델의 검증)

  • Chung Taeyoung;Lee Gunbok;Yi Kyongsu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.1
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    • pp.76-82
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    • 2005
  • In this paper, validation of Driver Steering Model has been conducted. The comparison between the simulation model and vehicle test results shows that the model is very feasible for describing combined human driver and actual vehicle dynamic behaviors. The 3D vehicle model is consisted of 6-DOF sprung mass and 4-quarter car model for vehicle body dynamics. Powertrain model including differential gear and Pacejka tire model are applied. The driver steering model is also validated with vehicle test result. The driver steering model is based on angle and displacement error from the desired path, recognized by driver.

EFFECTS OF THE VEHICLE MODEL ON SHIFTING TRANSIENTS OF PASSENGER CARS WITH AUTOMATIC TRANSMISSION

  • Kong, J.H.;Park, J.H.;Lim, W.S.;Park, Y.I.;Lee, J.M.
    • International Journal of Automotive Technology
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    • v.7 no.2
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    • pp.155-160
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    • 2006
  • This paper presents a vehicle model for analyzing the transient shifting characterisitics of a passenger car with automatic transmission. Then the presented vehicle model was linked with the dynamic model of an automatic transmission. In order to identify the parameters of the vehicle model, we installed a test equipment with an accelerometer in a conventional vehicle and performed road tests. With the proposed vehicle model, we simulated the dynamic characteristics during shifting, and benchmarked with experimental results. Moreover, a modal analysis was carried out to investigate the effect of the vehicle model in the frequency domain and to obtain the transfer function of the vehicle model. In addition, we showed the numerical results in the time domain for analyzing the effect of each stiffness element, such as engine mountings and suspensions.

Validation of the vehicle dynamic model for the static vehicle testing (정차상태 시험 결과를 이용한 차량동특성 해석 모델의 검증)

  • Park, Kil-Bae;Seong, Jae-Ho
    • Proceedings of the KSR Conference
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    • pp.317-325
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    • 2011
  • Vehicle model validation for the static vehicle testing has been done by comparison of the simulation results and test results and the parameters of the vehicle model to be used in the simulation have been adjusted to reflect the measured behaviour. The vehicle model fort the simulation should be validated by suitable tests and/or practical experience. The static vehicle test used to validate the vehicle model are the weight measurement, the wheel offloading test, the bogie rotational resistance test and the sway test. Finally, the computer simulation model has been validated and using the validated vehicle model the acceptance of the vehicle safety of the resistance to flange climbing derailment at low speed can be examined.

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The Handling Characteristics of The Independent Rear Wheel Steering Vehicle Using the Reference Model Following Control (기준모델 추종제어를 이용한 독립 후륜조향 차량의 조향 특성해석)

  • 봉우종;이상호;이언구;한창수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.4
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    • pp.130-140
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    • 2000
  • In this paper the reference model following control(RMFC) scheme through the optimal control theory is investigated for the independent rear wheel steering(IRWS) vehicle. RMFC vehicle follows the dynamic performance of a virtual vehicle as a reference model deisgned in the controller. Linear vehicle model of two degres-of-freedom is used to derive control scheme which is applied to full vehicle for evaluating handling performances. And 4WS vehicle through RMFC is compared to the conventional 2WS vehicle and 4WS vehicle in the J-turn test. The RMFC logic is also extended to IRWS vehicle, IRWS with RMFC shows not only the excellent handling performance but salso some advantages in terms of the directional stability and responsiveness from the simulation results.

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Development of a Real-Time Vehicle Dynamic Model for a Tracked Vehicle Driving Simulator

  • Lee, Ji-Young;Lee, Woon-Sung;Lee, Ji-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • pp.115.2-115
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    • 2002
  • A real-time vehicle simulation system is a key element of a driving simulator because accurate prediction of vehicle motion with respect to driver input is required to generate realistic visual, motion, sound and proprioceptive cues. In order to predict vehicle motion caused by various driving actions of the driver on board the simulator, the vehicle model should consist of complete subsystems. On this paper, a tracked vehicle dynamic model with high efficiency and effectiveness is introduced that has been implemented on a training driving simulator. The multi-body vehicle model is based on recursive formulation and has been automatically generated from a symbolic computation package develop...

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Mathematical Model for Power Transmission - Vehicle System Coupling Analysis (동력전달계와 차량계의 연성 해석을 위한 수학적 모델의 개발)

  • Kong, Jin-Hyung;Park, Jin-Ho;Jo, Han-Sang;Park, Yeong-Il;Lee, Jang-Moo
    • Proceedings of the KSME Conference
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    • pp.696-701
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    • 2000
  • In this study, a mathematical model fur analyzing the shift characteristics is proposed. The proposed model comprises power transmission system and vehicle system, which are coupled. And On-road car test is carried out in order to extract model parameters. Tile model is composed of a detailed powertrain, an engine/AT housing, a simplified suspension system. tires and a vehicle body model. On the test, the vehicle accelerations and pitch ratio are measured by using accelerometers and gyro sensor. The other data, for example speeds, a throttle position and a brake signal, are taken from sensors which already exist in the vehicle. Using natural frequency and characteristic equation, vehicle model parameters are extracted from experimental data.

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