• Title/Summary/Keyword: Active/semiactive suspension system

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A Study on the Knowledge Based Control Algorithm for Performance Improvement of the Automotive Suspension System (현가장치의 성능향상을 위한 지능형 제어로직에 관한 연구)

  • So, S.G.;Byun, G.S.
    • Journal of Power System Engineering
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    • v.5 no.2
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    • pp.87-92
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    • 2001
  • Automotive suspension system is a mechanism for isolation of the vibration coming from the road inputs. Recently, the electronically controlled suspension systems which may improve ride and handling performance have been developed. Here, the continuously controlled semi-active suspension system is focused. As a mechanism to control damping forces continuously, a solenoid valve is used. The modeling for the solenoid valve is introduced briefly, a vehicle dynamics modeling is constructed, and then combined system model is completed. To design the efficient control algorithm for the semiactive suspension system the knowledge based fuzzy logic is applied and the technique how to apply the sky-hook theory to the fuzzy logic is developed. Finally, to confirm the improvement of performance the computer simulation is carried out.

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An Emphirical Closed Loop Modeling of a Suspension System using a Neural Networks (신경회로망을 이용한 폐회로 현가장치의 시스템 모델링)

  • 김일영;정길도;노태수;홍동표
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.384-388
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    • 1996
  • The closed-loop system modeling of an Active/semiactive suspension system has been accomplished through an artificial neural Networks. The 7DOF full model as the system equation of motion has been derived and the output feedback linear quadratic regulator has been designed for the control purpose. For the neural networks training set of a sample data has been obtained through the computer simulation. A 7DOF full model with LQR controller simulated under the several road conditions such as sinusoidal bumps and the rectangular bumps. A general multilayer perceptron neural network is used for the dynamic modeling and the target outputs are feedback to the input layer. The Backpropagation method is used as the training algorithm. The modeling of system and the model validation have been shown through computer simulations.

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Influence of Semi-Active Suspension on Running Safety of Vehicles

  • Liu, Hong-You;Yu, Da-Lian
    • International Journal of Railway
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    • v.2 no.4
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    • pp.147-151
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    • 2009
  • Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is proposed. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operation safety of cars fitted with semiactive suspension system is analyzed. The results show that the vehicles equipped with semi-active suspension system, not only the vibration of car body is decreased, it can also give little influence on running safety of cars, as a result, it will not endanger the running safety of cars.

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Influence of Semi-active Suspension on Running Safety of Vehicles

  • Liu, Hong-You;Yu, Da-Lian
    • International Journal of Railway
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    • v.3 no.2
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    • pp.68-72
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    • 2010
  • Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is desirable. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operational safety of cars fitted with semiactive suspension system is analyzed. The results show that in vehicles equipped with semi-active suspension system, while the vibration of car body is decreased, the running safety of cars is not affected to any significant degree. As a result, the ride quality is much improved with negligible deterioration of the running safety of cars.

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A study on the improvement of a suspension system adopting a semiactive on-off damper (반능동 단속형 감쇠기를 이용한 현가장치 개선에 관한 연구)

  • 최성배;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.959-967
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    • 1988
  • In this paper, 2-DOF vehicle suspension system with a semiactive on-off damper was studied for improving the ride comfort. It is known that a nonlinear hydraulic damper, which generates force proportional to the square of the relative velocity, can describe the actual fluid resisting type damper more properly than the traditional viscous damping model. On the other hand, hydraulic damper adoption in analysis makes the system nonlinear and causes difficulties to get the system response. In this work, time domain direct integration method was used to calculate system displacement and acceleration. first of all, the response of the suspension system experiencing a given road profile was optimized by Lagrangian multiplier method within the range of given damping coefficients. The appropriate on-loaf damping values were obtained by averaging the already calculated optimum damping coefficients from Lagrangian techniques. The criterion to control the on-off mechanism was determined by examining the suspension efficiency. It was found that the best out of practically applicable criteria is following the sign (positive and negative) of the multiplication of relative displacement and velocity. Judging from the theoretical calculations, it was proved that the semiactive on-off damper can increase suspension efficiency as much as 8-11% in object function.

Semiactive MR Fluid Suspension System Using Frequency Shaped LQ Control (주파수 성형 LQ제어기를 이용한 반능동식 자기유변유체 현가 시스템)

  • Kim, Gi-Deok;Jeon, Do-Yeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2274-2282
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    • 2000
  • An MR(Magneto-Rheological) fluid damper is designed and applied to the semi-active suspension system of a 1/4 car model. The damping constant of the MR damper changes according to input current and the time delay of the damper is included in the system dynamics. The passive method, LQ control and Frequency shaped LQ control are compared in experiments. The advantage of the proposed frequency shaped LQ control is that the ride comfort improves in frequency range from 4 to 8Hz where human body is most sensitive and the driving safety improves around the resonance frequency of unsprung mass, 11Hz. The experiments using a 1/4 car model show the effectiveness of the algorithm.

Adaptive LQG Control for Semi -Active Suspension Systems: Disturbance Rejection Capability

  • Sohn, Hyun-Chul;Hong, Kyung-Tae;Hong, Keum-Shik
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.47.5-47
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    • 2001
  • In this paper. a road-adaptive LQG control for the semiactive Macpherson strut suspension system of hydraulic type is investigated. A new control oriented model, which incorporates the rotational motion of the unsprung mass, is introduced. A semi-active suspension controller adapting to road variations is proposed. First, based on the extended least squares estimation algorithm, a LQG controller adapting to the estimated road characteristics is designed. Through the computer simulations, the performance of the proposed semi-active suspension is compared with that of a non-adaptive one. The results show better control performance of the proposed system over the compared one.

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A Strategy to Evaluate Semi-Active Suspension System using Real-Time Hardware-in-the-Loop Simulation (실시간 Hardware-in-the-Loop 시뮬레이션을 이용한 반능동 현가시스템 특성 평가)

  • Choi, G.J.;Noh, K.H.;Yoo, Y.M.;Kim, H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.6
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    • pp.186-194
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    • 2001
  • To meet the challenge of testing increasingly complex automotive control systems, the real-time hardware-in-the-loop(HIL) simulation technology has been developed. In this paper, a strategy for evaluation of semiactive suspension systems using real-time HIL simulation is presented. A multibody vehicle model is adopted to simulate vehicle dynamic motions accurately. Accuracy of the vehicle simulation results is compared to that of the real vehicle field test and proven to be very accurate. The controller and stepping motor to adjust semi-active damper stage are equipped as external hardwares and connected to the real-time computer which has vehicle dynamic model. Open and closed loop test methods are used to evaluate a controlled suspension system and the system's operations are verified it is found that the proposed evaluation methods can be used well for the verification of semi-active suspension systems.

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Empirical Closed Loop Modeling of a Suspension System Using Neural Network (신경회로망을 응용한 현가장치의 폐회로 시스템 규명)

  • Kim, I.Y.;Chong, K.T.;Hong, D.P.
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.7
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    • pp.29-38
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    • 1997
  • A closed-loop system modeling of an active/semiactive suspension system has been accomplished through an artificial neural network. A 7DOF full model as a system's equation of motion has been derived and an output feedback linear quadratic regulator has been designed for control purpose. A training set of a sample data has been obtained through a computer simulation. A 7DOF full model with LQR controller simulated under several road conditions such as sinusoidal bumps and rectangular bumps. A general multilayer perceptron neural network is used for dynamic modeling and target outputs are fedback to the a layer. A backpropagation method is used as a training algorithm. Model validation of new dataset have been shown through computer simulations.

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Advanced Railway Vehicle Technology using Smart Materials (지능재료를 이용한 차세대 철도차량기술)

  • Kim, Jae-Hwan;Kang, Bu-Byoung;Kim, Kyeong-Jin;Chung, Heung-Chai;Choi, Sung-Kyu
    • Journal of the Korean Society for Railway
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    • v.6 no.4
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    • pp.252-256
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    • 2003
  • Smart materials can adapt to changes of environment like living organs in nature such that they can maximize the performance and minimize the maintenance expense of engineering systems. Such materials have been paid attention ten years ago and applied in the area of industry, aerospace, transportation and civil structures. This paper summarizes smart material technology and shows some application examples in railway vehicles. Also, its future of smart material technology in railway vehicle technology is envisaged based on its possibility and practical aspect.