• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.5
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• pp.519-525
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• 2010

The finite element (FE) method is generally used to model and simulate the physical behavior of large structures, such as passenger vehicles or aircraft. However, FE analysis involves a very large computation time and cost for developing the analysis model. Therefore, the vibration characteristics of large structural systems are often analyzed using the component mode synthesis (CMS) method, which is one of the substructure synthesis methods. In this study, the vibration characteristics of passenger vehicles are analyzed by using the substructure synthesis method. A passenger vehicle model, which includes a vehicle body, suspension systems, and a sub-frame, is presented. The physical components of the vehicle system are modeled as equivalent substructures using the Craig-Bampton method of CMS. The vibration characteristics, such as the natural frequencies and mode shapes and frequency response, of the vehicle system are determined. The effects of variations in some design parameters on the vibration characteristics of the full vehicle model are also investigated.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.10
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• pp.958-966
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• 2007

This study presents full vehicle dynamics model for the dynamic characteristic analysis of chassis parts which are suspension and brake system. This vehicle dynamics model is appled to kinematics and quasi-static analysis for each chassis part. In order to develop the vehicle dynamics model, the parameters of each chassis element part which are bush, spring and damper are measured by experiment. Also the wheel forces and moments of 6 DOF are measured at each wheel center. These data are applied to input parameter for vehicle dynamics model. And the verification of the developed model is achieved to comparison with the experimental force data of spring, trailing arm and assist arm by using the load response by strain gauge. These experimental force data are acquired by road test at event surfaces of P/G which are belgian and chuck holes roads.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.156-157
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• 2017

본 논문은 전차원 자속 관측기를 이용한 대용량 매입형 영구자석 동기전동기(IPMSM)의 센서리스 제어 기법을 제안한다. 기존의 전차원 자속 관측기를 사용한 제어 방식은 IPMSM의 자속 모델을 표면 부착형 영구자석 동기전동기(SPMSM)의 자속 모델처럼 해석하기 때문에 추정되는 회전각의 오차가 발생한다. 특히 릴럭턴스 토크가 큰 대용량 IPMSM 구동 시에는 회전각 오차가 크게 나타나므로 단위 전류당 발생하는 최대토크를 감소시켜 정밀한 MTPA 제어가 불가능하다. 제안하는 알고리즘은 전차원 자속 관측기를 통해 추정된 회전각의 오차를 보상하여 대용량 IPMSM의 정밀한 센서리스 제어를 가능하게 한다. 제안하는 기법의 타당성은 시뮬레이션을 통해 확인하였으며, 기존의 알고리즘과 비교하였다.

• 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.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.827-831
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• 2012

Passengers and mounted equipments on a vehicle are exposed to the vibration when it is driven on the road. To minimize the vibration and improve the dynamic characteristics of a vehicle are important factors. Those are changed by modifying parameters of the vehicle. To save development cost and time, simulation methods using vibration model have been widely used before making the real vehicle. In this paper two aimed functions, displacement between wheels and the body and acceleration of the body, have been defined for the parameter sensitivity analysis of the large vehicle. Full Vehicle Model having 11 degrees of freedom applied to solve those issues.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.92-100
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• 2003

Using a quarter car model, an analytic method for performance estimation of a vehicle suspension system with respect to frequency response, RMS response and performance index is presented. From frequency response function, compromization of response performance to the whole frequency range is verified and from RMS response and performance index, sensitivity of ride md handling characteristics are examined. Using a full car model, sweet area(stable ride area) are determined and performance sensitivity is estimated according to the change of feedback gains. In order to esimate the output sensitivity, response we is displayed using a 3-dimensional contour plot. Design data n suggested for optimal design parameter esimation, which maximize the performance of the given suspension system.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1144-1150
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• 2009

Appropriate vibration model is required to predict in advance the vibration level of a large vehicle which carries sensitive electronic/mechanical equipments and drives often on the unpaved and/or off-road conditions. Central tire inflation system(CTIS) is recently adopted to improve the mobile operation of military and bulletproof vehicles. In this paper, full vehicle model(FVM) having 11 degrees of freedom and equipped with CTIS has been developed for a large vehicle which has $8\times8$ wheels$\times$driving wheels. Usability of the developed model is validated via road tests for three different modes (i.e. highway, country, and mud/sand/snow modes) and for various velocity conditions. The developed FVM can be used to predict the vibration level of the large vehicle as well as to determine the driving velocity criterion for different road conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.863-867
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• 2011

In this paper, we analyze the characteristic test results of an MR damper for a cruise bus, and we model the nonlinear hysteretic characteristics of the damper using arctangent and polynomial functions. We establish an experimental model of the MR damper according to the input current, and we set the model parameters using the MATLAB Optimization Toolbox. The model is verified via a computer simulation of a full-car model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.160-166
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• 2018

This paper proposes an advanced suspension system and reports its performance in the framework of the preview control algorithm based on the RPS (road profile sensing) system and MSD system with the multi-stage damping characteristics. Typical disturbance inputs that cause excessive vibration and steering instability of an automobile are irregular obstacles that protrude or sink into the road surface to be driven. The control performance can be improved if information on the existence and shape function of its obstacle is known. Based on the results of the previous study, advanced research that uses the actuating system has been processed to be commercialized practically. For this purpose, a switching algorithm between the control logic and the multi-stage damping system was developed and its connectivity is presented. To verify the applicability of an actual vehicle, the proposed control system was implemented in full vehicle models and simulations were performed. The proposed system using the 3-DS actuator system, which is applied for structural simplicity, can improve the ride comfort and steering stability. In addition, the results indicate the feasibility of the intelligently controlled suspension system.