• 제목/요약/키워드: active suspensions

검색결과 56건 처리시간 0.022초

상용 차량용 반능동 현가 시스템의 제어 (Control of Semi-Active Suspensions for Commercial Vehicles)

  • 이경수;정준채
    • 한국자동차공학회논문집
    • /
    • 제6권6호
    • /
    • pp.98-106
    • /
    • 1998
  • In this study a control law and performance potential of semi-active suspensions for a tractor/semi-trailer have been investigated. The control law for airbag semi-active suspensions modeled in this study is developed using feedback linearization and Linear Quadratic (LQ) optimal control method. Inherent nonlinearity of the airbag suspensions has been considered in the control law development. It has been shown that the proposed semi-active control law provides better performance than that of well known sky-hook damping control strategy.

  • PDF

주행 상황을 고려한 차량 능동 현가장치 제어기 설계 (Design of A Controller for Vehicle Active Suspensions Considering Driving Conditions)

  • 천종민;이종무;권순만;최영규
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제54권12호
    • /
    • pp.698-704
    • /
    • 2005
  • Passive suspensions with fixed design constants are very restrictive in the inherent suspension problem, the trade-off between the ride quality and the suspension travel. Active suspensions are used to solve some drawbacks of passive suspensions. In this paper, we propose a controller design for vehicle active suspensions considering variable driving conditions. Our controller estimates the current driving conditions by detecting the road frequencies gotten from Fourier Transform and decides which factor must be emphasized between the ride quality and the suspension travel. In one case of focusing on the ride quality, we use the skyhook control law and in the other case of focusing on the suspension travel, the double skyhook control law is used. The control law modified by various road situations outputs the reference force value the electro-hydraulic actuator in active suspension system must generate. To track the reference force, we adopt the sliding control law which is very useful in controlling the nonlinear system like the electro-hydraulic actuator.

승용차용 반능동 현가시스템의 제어 (Control of Semi-active Suspensions for Passenger Cars(I))

  • 조영완;이경수
    • 대한기계학회논문집A
    • /
    • 제21권12호
    • /
    • pp.2179-2186
    • /
    • 1997
  • In this paper, the performance of a semi-active suspension system for a passenger car has been investigated. Alternative semi-active suspensions control laws has been compared via simulations. The control laws investigated in this study are : sprung mass velocity feedback control law, sky-hook damping control law, and state feedback control law. Simulation results show that a semi-active suspension has potential to improve ride quality of automobiles.

승용차용 반능동 현가시스템의 제어 (Control of Semi-active Suspensions for Passenger Cars(II))

  • 조영완;이경수
    • 대한기계학회논문집A
    • /
    • 제21권12호
    • /
    • pp.2187-2195
    • /
    • 1997
  • A semi-active suspension test system was designed and built for the experimental study. Vehicle parameters were estimated through tests and a quarter-car model was validated by comparing computer simulation results and laboratory test results. Alternative semi-active suspension control laws have been tested using the test system. Modulable damper used in this study is a "reverse" damper with 42 states which is controlled by a stepper motor. Experimental results have shown that semi-active suspensions have potential to improve ride quality of automobiles.tomobiles.

이동 로봇의 서스펜션 댐핑계수 변화에 따른 장애물이 있는 경사로 주행에 관한 연구 (Study on Driving a Bumped Slope of Mobile Robot According to Changing the Damping Coefficient of Suspensions)

  • 전봉수;김자영;이지홍
    • 로봇학회논문지
    • /
    • 제11권2호
    • /
    • pp.83-91
    • /
    • 2016
  • Most of outdoor mobile robots have a suspension on each wheel in order to relieve the shock by ground obstacles and to improve the driving stability. Typically, in the actual operations, the suspensions have been used under a given set of conditions as all the damping and spring coefficients of the suspensions are fixed. However, it is necessary to readjust the coefficients of the suspensions according to surface conditions that may cause the unstable shaking of a robot body at high speed driving. Therefore, this paper is focused on the mobility analysis of an outdoor robot when the coefficients of suspensions (in particular, damping coefficients) are changed while driving on an uneven road surface. In this paper, a semi-active suspension with twelve damping coefficient levels was used and a small sized vehicle with the suspensions was employed to analyze the mobility dependent on a change of the damping coefficient. And the mobility was evaluated through driving experiments on a bumped slope.

Force control of an asymmetric hydraulic cylinder for active suspensions

  • Kim, Wanil;Lee, Byung-Youn;Won, Sang-Chul
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
    • /
    • pp.1124-1127
    • /
    • 1996
  • Asymmetric cylinders are usually used as an actuator of active suspensions. Since the force is influenced not only by the control but by the road roughness, force control is needed to track the desired force. But the conventional error feedback control treats the valve-cylinder dynamics at its operating point and many use the symmetric model which differ in all respects. We adopt an asymmetric cylinder model and apply a feedback linearization method for the force control to compensate both the valve nonlinearities and the effects of the road roughness.

  • PDF

자기부상열차 현가장치의 능동진동제어 (Active vibration control of the secondary suspension for the magnetic levitation vehicle)

  • 강정식;강이석
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
    • /
    • pp.876-879
    • /
    • 1996
  • The vibration of an attractive magnetic levitation(Maglev) vehicle transportation system is caused by the irregularity of the guideway track and the performance of the suspensions of the Maglev system. It is essential for us to give attention to the secondary suspension of the vehicle system as it determines the ride quality. In order to improve the ride quality and running stability, active secondary suspensions have been developed and applied to the vibration problems. This paper analyzes the performance of the active secondary suspension which is applied to an attractive magnetic levitation vehicle system running on a rough track. The dynamics of the suspension system and the optimal control problems are studied. According to the transient and frequency response analyses to the track disturbance, the ride quality of an attractive Maglev vehicle has been improved by applying the designed LQR active controller, and it has been confirmed that this improvement was also influenced by the configuration of the system.

  • PDF

차량의 능동형 현가장치를 위한 강인한 $H^{\infty}$ 제어기 설계 (A Robust $H^{\infty}$ Controller for Active Suspensions Based on a Full-Car Model)

  • 박종현;김영석
    • 제어로봇시스템학회논문지
    • /
    • 제6권2호
    • /
    • pp.146-154
    • /
    • 2000
  • An $H\infty$ controller is designed for active suspensions of vehicles using 7-degree-of-freedom full-car model. Its performance robustness as well as stability robustness to system parameter variations and unmodelled dynamics are assured through the $\mu$-framework. The performance of the $H\infty$ controller is compared with that of a LQC controller in compute simulations. From the simulations it is found that the active suspension with the $H\infty$ controller reduces the acceleration and motion of the sprung mass in the heaving rolling and pitching directions when the car is driven on a normal road or through an asymmetric bump. The suspension stroke and the road holding capability are also improved with a relatively small level of power consumption. Overall the $H\infty$ controller shows a more robust performance than that of the LQG design.

  • PDF

도시형 전동차를 위한 능동조향대차시스템의 적용가능성 고찰 (Possibility Investigation of the Active Steering Bogie System for a Urban Railway Vehicle)

  • 박준혁;유원희
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2007년도 춘계학술대회 논문집
    • /
    • pp.715-721
    • /
    • 2007
  • On a conventional rail vehicle, passive primary suspensions stabilize wheelsets in the longitudinal and yaw direction. However, these suspensions reduce the natural curving ability due to the profile of the wheels. Stabilizing and steering of the wheelsets generate the conflict problems in design process. Therefore, most systems are designed to guarantee the stability in spite of decreased curving performance. As a result, severe wear of the wheels and rails occur on tight curves and squeal noise on curving is high. Active steering has been proposed to satisfy stabilizing and steering performance simultaneously. This paper describes the possibility investigation about the application of the active steering bogie for a urban railway vehicle. Vehicles run on an amount of tight curves at mid or low speed in urban railways. Thus, it is important to reduce the wear and squeal noise between wheels and rails. Simulations show that active steering can be reduce the wear and squeal noise significantly compared to conventional systems.

  • PDF

제한 대역폭을 가진 능동 현가 장치에 대한 Look-ahead 예견 제어-궤도 차량에의 응용 (Look-ahead Preview Control with Limited Bandwidth Active Suspension - Application to Tracked Vehicle Systems)

  • 유성필;박영진;박윤식
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2005년도 추계학술대회논문집
    • /
    • pp.209-212
    • /
    • 2005
  • The look-ahead preview control with the use of limited bandwidth active suspensions is presented. Both a linearized racked vehicle model and a complex nonlinear model based on a commercial multibody dynamic program are used to verify the performance of preview control. The performance of the preview control system is evaluated on the ride quality which is estimated from the acceleration of the driver position. Due to the practical advantages associated with the use of limited bandwidth active control in comparison with full bandwidth systems, the results are considered important to the future development of active tracked vehicle suspensions.

  • PDF