• Title, Summary, Keyword: semi-active system

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Experimental Study of Design for Semi - Active suspension system for Railway Vehicle with narrow gauge (협궤 차량용 준능동형 현가 시스템 설계의 시험적 연구)

  • Lee Nam-Jin;Kim Chul-Gun;Nam Hak-Gi
    • Proceedings of the KSR Conference
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    • pp.811-815
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    • 2005
  • Traditional passive suspension has limitations to meet the required specifications of high level trains, and so Active suspension system is proposed to meet the requirements with active components which could be controlled by external signal for optimized behavior of train. Active suspension is to be divided by Full active suspension and Semi-active suspension whether using the external power source or not, and though the performance of Semi-Active suspension is worse than Full one. Semi-active suspension is focused with its effectiveness per cost. Semi-Active suspension system consists of sensors, ECU (electrical control unit), and variable damper, which are to be designed to be fit for train system. And the software of ECU is to be developed for to be suited to its dynamic behavior through simulation result calculated by proven model. In this experimental study, the hardware and software of semi-active suspension system is to be realized and its performance for improvement of ride quality to be confirmed through roller rig test.

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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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Semi-active control of seismic response of a building using MR fluid-based tuned mass damper

  • Esteki, Kambiz;Bagchi, Ashutosh;Sedaghati, Ramin
    • Smart Structures and Systems
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    • v.16 no.5
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    • pp.807-833
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    • 2015
  • While tuned mass dampers are found to be effective in suppressing vibration in a tall building, integrating it with a semi-active control system enables it to perform more efficiently. In this paper a forty-story tall steel-frame building designed according to the Canadian standard, has been studied with and without semi-active and passive tuned mass dampers. The building is assumed to be located in the Vancouver, Canada. A magneto-rheological fluid based semi-active tuned mass damper has been optimally designed to suppress the vibration of the structure against seismic excitation, and an appropriate control procedure has been implemented to optimize the building's semi-active tuned mass system to reduce the seismic response. Furthermore, the control system parameters have been adjusted to yield the maximum reduction in the structural displacements at different floor levels. The response of the structure has been studied with a variety of ground motions with low, medium and high frequency contents to investigate the performance of the semi-active tuned mass damper in comparison to that of a passive tuned mass damper. It has been shown that the semi-active control system modifies structural response more effectively than the classic passive tuned mass damper in both mitigation of maximum displacement and reduction of the settling time of the building.

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 Field Test Characteristics of Semi-Active Suspension System with Continuous Damping Control Damper (감쇠력 가변댐퍼를 이용한 반능동 현가장치의 실차실험 특성에 관한 연구)

  • Lee, K.H.;Lee, C.T.;Jeong, H.S.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.7 no.4
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    • pp.32-38
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    • 2010
  • A semi-active suspension is an automotive technology that controls the vertical movement of the vehicle while the car is driving. The system therefore virtually eliminates body roll and pitch variation in many driving situations including cornering, accelerating, and braking. This technology allows car manufacturers to achieve a higher degree of both ride quality and car handling by keeping the tires perpendicular to the road in corners, allowing for much higher levels of grip and control. An onboard computer detects body movement from sensors located throughout the vehicle and, using data calculated by opportune control techniques, controls the action of the suspension. Semi-active systems can change the viscous damping coefficient of the shock absorber, and do not add energy to the suspension system. Though limited in their intervention (for example, the control force can never have different direction than that of the current speed of the suspension), semi-active suspensions are less expensive to design and consume far less energy. In recent time, the research in semi-active suspensions has continued to advance with respect to their capabilities, narrowing the gap between semi-active and fully active suspension systems. In this paper we are studied the characteristics of vehicle movement during the field test with conventional and semi-active suspension system.

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Semi-active fuzzy based control system for vibration reduction of a SDOF structure under seismic excitation

  • Braz-Cesar, Manuel T.;Barros, Rui C.
    • Smart Structures and Systems
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    • v.21 no.4
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    • pp.389-395
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    • 2018
  • This paper presents the application of a semi-active fuzzy based control system for seismic response reduction of a single degree-of-freedom (SDOF) framed structure using a Magnetorheological (MR) damper. Semi-active vibration control with MR dampers has been shown to be a viable approach to protect building structures from earthquake excitation. Moreover, intelligent damping systems based on soft-computing techniques such as fuzzy logic models have the inherent robustness to deal with typical uncertainties and non-linearities present in civil engineering structures. Thus, the proposed semi-active control system uses fuzzy logic based models to simulate the behavior of MR damper and also to develop the control algorithm that computes the required control signal to command the actuator. The results of the numerical simulations show the effectiveness of the suggested semi-active control system in reducing the response of the SDOF structure.

Design of Semi-Active suspension system for Railway Vehicle with narrow gauge (협궤 차량용 준능동형 현가 시스템 설계)

  • Lee Nam-Jin;Kim Chul-Gun;Nam Hak-Gi
    • Proceedings of the KSR Conference
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    • pp.473-478
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    • 2005
  • Active suspension system improves ride quality with optimized suspension force, generated by electric, hydrolic or pneumatic power and controlled by micro-processor under various operation condition of train, while Semi-Active susepsion system provides optimized and controlled characteristics of suspensions such as damping coefficient without external energy. The benefits fo Semi-Active suspension are no required power source and to be made compact with lower cost. Train with narrow gauge could be more unstable than one for normal or wide gauge, and it could be more vibrated than others one by external force such as aerodynamic force and track irregularity. So, the reduced ride quality could be improved with appling with Semi-active suspension system. In this report, the Semi-Active suspension system for narrow gauge train shall be proposed and to prepare the Roller Rig test of this train, integration of system, development of control algorithm and confirmation of its performance with simulation tool would be taken.

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H Control of Secondary Suspension in Railway Vehicles Equipped with a MR Damper (MR 댐퍼가 적용된 철도차량 이차현가장치의 H 제어)

  • Shin, Yu Jeong;You, Won Hee;Hur, Hyun Moo;Park, Joon Hyuk
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.10
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    • pp.1051-1059
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    • 2013
  • In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

Hydropneumatic Modeling and Dynamic Characteristic Analysis of a Heavy Truck Semi-active Cabin Air Suspension System (대형 트럭 반능동형 캐빈 공기 현가시스템의 유공압 모델링 및 동특성 해석)

  • Lee, Kwang-Heon;Jeong, Heon-Sul
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.2
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    • pp.57-65
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    • 2011
  • In this paper, a hydropneumatic modeling and dynamic analysis of a heavy truck semi-active cabin air suspension system is presented. Semi-active cabin air suspension system improves driver's ride comfort by controlling the damping characteristics in accordance with driving situation. So it can reduce vibration between truck frame and cabin. Semi-active cabin air suspension system is consist of air spring, leveling valve and CDC shock absorber, and full cabin system are mathematically modelled using AMESim software. Simulation results of components and full cabin system are compared with experimental data of components and test results of a cabin using 6 axis simulation table. It is found that the simulation results are in good agreements with test results, and the hydropneumatic model can be used well to predict dynamic characterics of heavy truck semi-active cabin air suspension system.

Cost-Effectiveness Evaluation of Semi-Active Control System for Cable-Stayed Bridge (사장교에 장착된 준능동형 제어시스템의 비용효율성 평가)

  • Hahm, Dae-Gi;Park, Won-Suk;Koh, Hyum-Moo;Ok, Seung-Yong;Park, Kwan-Soon
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • pp.388-395
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    • 2005
  • This paper presents cost-effectiveness evaluation of semi-active control system for cable-stayed bridge under earthquake excitation. Bi-state control method with Linear Quadratic Gaussian(LQG) optimal controller is used for generic semi-active dampers. Cost-effectiveness of the structural control system is investigated by using the life-cycle cost(LCC) concept. The evaluation results show that the efficiency of semi-active control system is increased when the damage cost due to the failure of bridge system or the bridge importance is enlarged. It was also found that the damper cost had little influence on the cost-effectiveness of semi-active control system if it was relatively small to the initial construction cost.

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