• 대한전기학회논문지
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• 제45권4호
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• pp.582-589
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• 1996

In this paper, an adaptive control problem of a hydraulic actuator for vehicle active suspension controller is divided into two parts: the inner loop controller and the outer loop controller. Inner loop controller, which is a nonlinear adaptive controller, is designed to control the force generated by the nonlinear hydraulic actuator acting under the effects of Coulomb friction. For simplicity of designing a nonlinear controller, the spool valve dynamics of a hydraulic actuator is reduced using a singular perturbation technique. The estimation error signal used to an indirect parameter adaptation is calculated without a regressor filtering. The absolute velocity of a sprung mass will be damped down by its negatively proportional term(sky-hook damper) adopted as an outer loop controller. Simulation results are presented to show the importance of controlling the actuator force and the validity of the proposed adaptive controller. (author). refs., figs. tab.

• 한국정밀공학회지
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• 제18권1호
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• pp.56-62
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• 2001

In this paper, skyhook control of a semi-active ER(Electro-Rheological) damper is investigated. The strength of the ER damper is controlled by a high voltage power supply. This paper deals with a two-degree-of-freedom suspension using the damper with ERF for a quarter vehicle system. The control law for semi-active suspensions modeled in this study is developed using skyhook and Linear Quadratic Regulator(LQR) optimal control method. Computer simulation and experimental results show that the semi-active suspension with ERF damper has good performances of ride quality.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.41.4-41
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• 2001

In this paper, we propose a LQR(Linear Quadratic Regulator) controller design for the active suspension using two-degree-of-freedom quarter-car model. We can improve the inherent suspension problem, the tradeoff between ride quality and suspension travel by selecting appropriate weights in the LQR-objective function. Because any definite rules for selecting weights do not exist, we replace the designer´s trial and error with the optimization-algorithm, ES(Evolution Strategy). Using the ES, we can find the proper control gains for selected frequencies, which have major effects on the vibrations of the vehicle´s state variables.

• 한국CDE학회논문집
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• 제19권4호
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• pp.316-323
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• 2014

This paper proposes the 3D modeling and simulation technique for predicting the integrated performance of combat vehicle. To consider the practical driving and firing condition of a combat vehicle, the full vehicle model, which can define the six degrees-of-freedom of vehicle motion and various firing angles, is developed. The critical design parameters such as the stiffness and damping coefficient of suspension system are applied to construct the analysis model of vehicle. A simple ballistic model, which incorporates the empirical interior ballistic model and the point mass trajectory model, is built to estimate the firing range and the firing recoil force. To predict the integrated performance and analyze the effect of system parameters, MATLAB/SIM-ULINK model of a combat vehicle for performing the real time simulation is also developed. Several simulation tests incorporating the road bump and the firing recoil force are presented to confirm the effectiveness of the proposed vehicle model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.305-306
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• 2013

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1194-1198
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• 1993

Active roll control can improve handling and ride comfort. Dynamic characteristics of the hydraulic actuators for active suspension, which can be modeled as the 1'st order time lag system, hinders the performance improvement. To overcome this shortcoming a predictive controller is designed based on 3 d.o.f. linear vehicle handling model. The effect of this controller is studied through the simulation based on 10 d.o.f. nonlinear vehicle model and the results is compared to that of feedforward controller which uses lateral acceleration as control signal.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1631-1638
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• 2007

In this paper, a modeling for the dynamic behavior of a train vehicle is suggested for the prediction of the braking characteristics. In the dynamic modeling, effects of the primary and secondary suspension elements are considered and interactions between two vehicles are also estimated. This study can offer some fundamental results for a further research to enhance the braking performance using active braking control.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.46-49
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• 1995

This paper deals with characteristics of magnet that the levitation and guidance forces at static state and we tested and evaluated its. Also we compared to effect of levitation force with material and shape of guide way, focus on evaluation and method of test for the magnet of Urban Transit Maglev vehicle.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1434-1439
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• 2012

차량은 여러 가지 설계변수가 결합된 동적계이다. 차량의 운동특성은 이러한 설계변수의 변화에 따라 변하게 된다. 설계변수의 조종안정성에 대한 영향을 파악하기 위하여 현가장치나 조향장치 특성이 포함된 등가코너링강성을 고려한 차량의 조종안정성 모델에 대하여 수치해법에 의한 민감도 해석을 수행하였다. 민감도 해석결과로부터 차량설계변수인 무게중심위치, 타이어 코너링특성, 현가장치 및 조향장치의 특성의 변화에 대한 정상상태이득, 스테빌리티 팩타, 주파수응답 등 차량 조종안정성의 변화율을 파악할 수 있었다. 또한 민감도 해석은 정성적이고 정량적인 결과를 제공하므로 설계단계는 물론 차량개발단계에서도 차량의 성능향상을 위한 설계변수들의 최적화에 사용될 수 있다.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.154-162
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• 2004

In this study, a mathematical model for analyzing the shifting transients of the passenger car with an automatic transmission is proposed. The proposed model comprises a power transmission system and a vehicle system, which are coupled. In order to extract the modeling parameters, on-road car test is carried out. The 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 a gyro sensor. The speeds, the brake signal, and the throttle position are taken from sensors which already exist in the vehicle. Considering natural ftequencies, which is calculated from the measured accelerations, and the characteristic equation, vehicle model parameters are identified. Dynamic behaviors during upshift or downshift are simulated using the proposed vehicle model. By comparing and analyzing the simulation result and on-road car test data, the vibration of the Engine/AT housing influences the shifting transients. The effect of model parameters are also studied. Among model parameters, the location of engine mountings influences the vibration of the vehicle body.