• 제목/요약/키워드: Suspension systems

검색결과 529건 처리시간 0.04초

Optimal Design of Discrete Time Preview Controllers for Semi-Active and Active Suspension systems

  • Youn, Il-Joong
    • Journal of Mechanical Science and Technology
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    • 제14권8호
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    • pp.807-815
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    • 2000
  • In this paper, modified discrete time preview control algorithms for active and semi-active suspension systems are derived based on a simple mathematical 4 DOF half-car model. The discrete time preview control laws for ride comfort are employed in the simulation. The algorithms for MIMO system contain control strategies reacting against body forces that occur at cornering, accelerating, braking, or under payload, in addition to road disturbances. Matlab simulation results for the discrete time case are compared with those for the continuous time case and the appropriateness of the discrete time algorithms are verified by the of simulation results. Passive, active, and semi-active system responses to a sinusoidal input and an asphalt road input are analysed and evaluated. The simulation results show the extent of performance degradation due to numerical errors related to the length of the sampling time and time delay.

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A Study on Strength Evaluation of a Road Wheel of Multipurpose Tracked Vehicles (다목적전술차량의로드휠강도평가에관한연구)

  • Kam M.K.;Kim H.S.;Kim Y.J.;Kim W.I.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.473-476
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    • 2005
  • Mobility of tracked vehicles is dependent on performance of its power equipment and suspension systems. Especially, its road wheels, components of its suspension systems, play an important role in distributing the vehicle weight on the ground and preventing from misguiding tracks. In this study, the maximum force acted on multipurpose tracked vehicles driven on the worst condition was calculated. And then FE analyses were carried out to evaluate the strength of the road wheels under the maximum force condition. For quality evaluation of the road wheels, FE simulations and experimental works were carried out under specific slant loads. Residual deformation for the slant loads was investigated and commented upon.

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A study on the performance of variable damper type suspension for tracked vehicle (가변댐퍼식 궤도차량용 현수장치의 성능에 관한 연구)

  • 이재순;김승무
    • Journal of the korean Society of Automotive Engineers
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    • 제3권2호
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    • pp.34-42
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    • 1981
  • The feasibility of using fluidic components for improving certain performance characteristics of the suspension systems for tracked vehicle is investigated. This study describes three variable damping systems for which the damping coefficients are function of relative velocity and absolute a of the vehicle body. Through the comparison analysis between constant damping coefficient damper and each of variable dampers. the followings were found: (1)Fluidic Diode Damper gave less accelerations, (2)Both Fluidic Diode Damper and Relative Velocity Damper gave the less time for which the wheel is off the ground, (3) At low vehicle velocity Fluidic Diode Damper gave low energy dissipation rate, while at high vehicle velocity Turbulence Accelerometer Damper gave low energy dissipation rate.

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A study on design and control of hydraulic test rig for performance evaluation of active suspension system (능동 현가시스템의 성능평가를 위한 유압식 시험기의 설계 및 제어에 관한 연구)

  • 손영준;이광희;이진걸
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1445-1449
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    • 1996
  • To evaluate of active suspension, it is necessary for special equipment - so called Test Rig which can perfectly realize the road condition and the impact from the road. And most of the test rig systems controlling force accurately and rapidly consist of electro-hydraulic servo mechanism, and they need robust controller which can endure outer road change. But in the case of PID controller, we should choose its best gains by trial and error method, and once its gains are fixed, they cannot get changed, so we should reset PID controller gains respectively when the road is changed. Therefore based on the load pressure feedback compensation method, our aim at constructing electro-hydraulic test rig is not affected by various road disturbance.

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Effect of Sugar Starvation on the Sugar Transport System in Suspension Cultures of Streptanthus trotus (Streptanthus tortus 배양 세포에서 당류고갈이 당류 수송계에 미치는 영향)

  • 조봉희
    • Korean Journal of Plant Tissue Culture
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    • 제27권1호
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    • pp.47-50
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    • 2000
  • In suspension cultures of Streptanthus. the uptake rate of sugar was increased during the ceil starvation of sugar in the medium. The maximal uptake rate obtained with 3 days of cell starvation. Sugar transport system induced by the sugar starvation was completely inhibited by 10 $\mu$M cycloheximide. Plant cells are known to possess only one sugar transport system, but the uptake rate of glucose obtained a saturated kinetic while the one of sucrose had two different kinetics after the sugar starvation. Induced sugar transport systems had different kinetics compared to plant cell. These results showed that higher plants have adaptable ability to induce new sugar transport systems when the environment changed unsuitable.

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High Tunable Control Algorithm for Semi-active Suspension by a Normal Type CDC Damper (연속 가변 댐퍼에 의한 반능동 현가장치의 고 자유도 제어기)

  • Choi, Ju-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • 제16권11호
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    • pp.1096-1103
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    • 2010
  • This paper proposes CDC (Continuous Damping Control) algorithm and verifies in multi-body dynamic vehicle. In order to distinguish a road profile on driving, waviness calculated by the filtered vertical-accelerations of sprung and unsprung masses is introduced. Sky-hook control is used at a low waviness road and constant damping level control is used at a high waviness road, where the hard damping level is determined by waviness, roll rate, acceleration, and deceleration. The damping levels of ride, anti-roll, anti-squat, and anti-dive modules are calculated by tuning parameters which is dependent upon vehicle velocity. Therefore this high tunable algorithm is useful to improve the ride and handling performance under various driving conditions. In the simulations, tire and dampers are modelled by SWIFT (Short Wavelength Intermediate Frequency Tire) model and 1st order delay model, and results are compared with conventional damper's.

A Study on The Vibration Reduction of a Driver Seat Controlling an MR Fluid Damper (자기유변유체 댐퍼를 이용한 운전석의 진동감쇠에 대한 연구)

  • 안병일;전도영
    • Journal of Institute of Control, Robotics and Systems
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    • 제8권10호
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    • pp.861-866
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    • 2002
  • A seat suspension system with a controlled MR(Magneto Rheological) fluid damper is introduced to improve the ride quality and prevent the health risk of a driver compared to fixed seats. The system is located between a seat cushion and the base, and is composed of a spring, MR fluid damper and controller. The MR fluid damper designed in valve mode is capable of producing a wide range of damping force according to applied currents. In experiments, a person was sitting on the controlled seat excited by a hydraulic system The skyhook control, continuous skyhook control and relative displacement control were applied and the continuous skyhook control improved the vibration suppression by 36.6%.

Modeling and Aalyzing Electromagnets for Magnetic Suspension Systems

  • Lee, Sang-Heon;Baek, Yoon-Su;Jung, Kwang-Suk
    • International Journal of Precision Engineering and Manufacturing
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    • 제7권4호
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    • pp.28-33
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    • 2006
  • Various precision engineering studies have attempted to remove mechanical friction, which causes the performance of a system to deteriorate, from precision positioning devices. Since the classical fluid lubrication method has some disadvantages in clean environments, attention has been focused on magnetic bearings and contact-free systems with their pollution-free characteristics. In this paper, f electromagnets are modeled and analyzed, not only for magnetic bearings but also for contact-free electromagnetic actuators. Three types of electromagnets that are appropriate for various applications were considered using magnetic circuitry theory. The results were experimentally validated.

Design of Robust Controller for Electromagnetic Suspension System with Kalman Filter (칼만 필터를 이용한 자기부상 시스템의 강인제어기 설계)

  • Jang, S.M.;Sung, S.Y.;Sung, H.K.;Jo, H.J.
    • Proceedings of the KIEE Conference
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.1411-1413
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    • 2000
  • Distubance of air-gap sensors by rail irregularities are the serious problem deteriorating the performance in the electromagnetic suspension (EMS) systems. Thus, this paper proposes the output feedback controller with discrete kalman filter for the EMS systems. The discrete kalman filter estimate true state value and output feedback controller guarantee stability. The benefit of this scheme are shown by simulation. Therefore air-gap disturbance are rejected successfully.

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Analysis of Slider Dynamics in Loading Process considering Collision (충돌을 고려한 Dynamic L/UL 슬라이더의 동적 거동 해석)

  • Kim, Bum-Joon;Rhim, Yoon-Chul
    • Transactions of the Society of Information Storage Systems
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    • 제2권2호
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    • pp.144-149
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    • 2006
  • Dynamic L/UL(Load/Unload) system has many merits. but it may happen an undesirable collision during the dynamic loading process. In this paper, the dynamics of negative pressure pico-slider was investigated through numerical simulation during the loading process. A simplified L/UL model for the suspension system has been presented and a simulation code has been developed to analyze the motion of the slider. A slider design has been simulated at various disk rotating speeds, skew angles of slider. We can decrease the possibility of collision and smoothen the loading process for a given slider-suspension design by selection an optimal rpm and pre-skew angle.

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