• Title/Summary/Keyword: 유공압 댐퍼

Search Result 15, Processing Time 0.026 seconds

Modeling of MR Damper Landing Gear Considering Incompletely Developed Fluid Flow (불완전 발달 유체 유동을 고려한 MR댐퍼 착륙장치 모델링)

  • Lee, Hyo-Sang;Jang, Dae-Sung;Hwang, Jai-Hyuk
    • Journal of Aerospace System Engineering
    • /
    • v.15 no.1
    • /
    • pp.7-18
    • /
    • 2021
  • A semi-active MR damper landing gear is a damper that generates a fluid damping force and a magnetic field control damping force when the MR fluid passes through annular flow paths. In the case of MR fluid passing through annular flow paths, an incompletely developed flow inevitably occurs, causing an error in calculating damper inner forces including the fluid damping force. This error results in an inaccurate design of damper structural parameters and control gain selection, resulting in deterioration of dynamic characteristics and shock absorption performance of the landing gear. In this paper, we derived a mathematical model of an MR damper landing gear considering additional damping force generated in the entrance region of annular flow paths of the MR damper. If the mathematical modeling derived from this paper is applied to the design and optimization process of an MR damper landing gear, excellent performance of the MR damper landing gear is expected.

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
    • /
    • v.19 no.2
    • /
    • pp.57-65
    • /
    • 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.

Experimental Study of Shoe Cushioning System of Shock Absorption Using Fluid Damper with Nano Particles (나노입자 유체댐퍼를 이용한 보행 충격 완화 장치의 충격 흡수에 대한 실험적 연구)

  • Moon B.Y.
    • Transactions of The Korea Fluid Power Systems Society
    • /
    • v.2 no.2
    • /
    • pp.14-20
    • /
    • 2005
  • This study developed and evaluated a shoe cushioning system to reduce impact force patterns during running. The shoe cushioning system is composed with a poly urethane pocket, which contains water and porous grains to absorb the force against the weight inside the pocket. Load-displacement curves for the shoe cushioning system were obtained from an instrumented testing machine and the results were compared with various pockets that have air, water or grains. Mechanical testings showed that the pocket with 5 g particles was the best for the shoe cushioning system. This founding will be helpful to designing the shoe.

  • PDF

Analysis of a Variable Damper and Pneumatic Spring Suspension for Bicycle Forks using Hydraulic-Pneumatic Circuit Model (유공압 회로를 이용한 자전거 포크용 가변댐퍼-공압스프링 서스펜션의 해석)

  • Chang, Moon Suk;Choi, Young Hyu;Kim, Su Tae;Choi, Jae Il
    • Journal of Drive and Control
    • /
    • v.16 no.1
    • /
    • pp.7-13
    • /
    • 2019
  • The objective of this study was to present a damped pneumatic suspension, a bike fork suspension, which can adapt itself to incoming road excitations is presented in this paper. It consists of a hydraulic damper and a pneumatic spring in parallel with a linear spring. The study also proposed a variable and switchable orifice, in the hydraulic damper, to select appropriate damping property. Hydraulic-pneumatic circuit model for the bike fork suspension was established based on AMESim, in order to predict its performance. In addition, elastic-damping characteristics of the fork such as spring constant and viscous damping coefficient were computed and compared, for validation, with those evaluated by experiment using the universal test machine. Through simulation analysis and test, it was established that the hydraulic-pneumatic circuit model is effective and practical for development of future MTB suspensions.

Design of a Robust Controller for a Watertight Damper Driving System (수밀댐퍼 구동장치의 강인제어에 관한 연구)

  • Han, Seung Hun;Jang, Ji Seong
    • Journal of Drive and Control
    • /
    • v.14 no.2
    • /
    • pp.45-51
    • /
    • 2017
  • Semi-submersible drilling rigs are offshore plants that perform functions such as ocean exploration for oil and gas acquisition, drilling and production, and storage and unloading of crude oil and gas. Semi-submersible drilling rigs use watertight dampers as emergency buoyancy holders. Since the watertight damper is an emergency shutoff device, it is mainly driven by a pneumatic driving system that can operate without a power supply. The pneumatic driving system has highly non-linear characteristics due to compressibility of air and external disturbance such as static and Coulomb friction. In this paper, a new control algorithm is proposed for a watertight damper driving system based on the sliding mode control with a disturbance observer. To evaluate control performance and robust stability of the designed controller, the control results were compared with the results obtained using the state feedback controller. As a result, it was confirmed that the pneumatic driving system for driving the watertight damper using the sliding mode controller with a disturbance observer can obtain excellent control performance against the parameter changes and the disturbance input.

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
    • /
    • v.7 no.4
    • /
    • pp.32-38
    • /
    • 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.

  • PDF

Study on the Damping Mechanism of an Hydraulic Type Automotive Seat Damper (자동차용 유압식 시트댐퍼의 댐핑 메카니즘에 관한 연구)

  • Lee, Choon Tae
    • Journal of Drive and Control
    • /
    • v.13 no.4
    • /
    • pp.1-6
    • /
    • 2016
  • Typically, the seat of an automotive vehicle generally includes a horizontal seat-cushion portion and a vertical seat-back portion that is operatively connected to the seat-cushion portion. The seat may include a recliner for the reclining of the seat-back portion relative to the seat-cushion portion by the seat occupant. An energy absorber or damper can also be provided for the seat-back portion. Because the recliner is configured to be released at a relatively high speed, and it results in an impact at the end of a folding stroke, the damper needs to dissipate energy as the seat back moves with respect to the seat cushion; therefore, the role of the seat damper in the automotive-seat design is important. In this paper, the mechanism of an hydraulic-type automotive-seat damper is investigated, and the torque characteristic is simulated according to the design-parameter variations such as the orifice area and the working-fluid properties.

A Study on the Torque Characteristics of Rotary Dampers (로터리 댐퍼의 토오크 특성에 관한 연구)

  • Lee, Choon Tae
    • Journal of Drive and Control
    • /
    • v.16 no.4
    • /
    • pp.87-92
    • /
    • 2019
  • Rotary dampers are damping devices which provide high resistance to shaft rotation. Rotary dampers are being used in various areas to enable the gentle opening and closing of the rotation motion relative to home furniture, industry machinery and automotive parts. Rotary dampers can be installed directly at the rotating point of a various part and can achieve uniform, gentle movement which increases quality and value of products. And generally, the silicone fluid is used as the damping medium because of its stable viscous properties. The movement of these little decelerators can be achieved with a high viscosity of working fluid and throttles installed in the body of the rotary damper. The damping force can be achieved clockwise, anti-clockwise or in both directions according to the structure of the orifices or throttles. In this paper, the torque performances of the rotary damper containing air in the working fluid were studied. For this purpose, the torque characteristic of the rotary damper according to the variation of various operating conditions such as clearance of leakage, dimensions of groove orifice, content ratio of air, etc., were simulated with AMEsim software.

Development and Evaluation of a Hybrid Damper for Semi-active Suspension (반능동 현가장치의 하이브리드형 댐퍼 개발에 관한 연구)

  • Jin, Chul Ho;Yoon, Young Won;Lee, Jae Hak
    • Journal of Drive and Control
    • /
    • v.15 no.1
    • /
    • pp.38-49
    • /
    • 2018
  • This research describes the development model and testing of a hybrid damper which can be applicable to a vehicle suspension. The hybrid damper is devised to improve the performance of a conventional passive oil damper using a magneto-rheological (MR) accumulator which consists of a gas accumulator and a MR device. The level of damping is continuously variable by the means of control in the applied current in a MR device fitted to a floating piston which separates the gas and the oil chamber. A simple MR device is used to resist the movement of floating piston. At first a mathematical model which describes all flows within the conventional oil damper is formulated, and then a small MR device is also devised and adopted to a mathematical model to characterize the performance of the device.

A Study of the Hydraulic Circuit Model for a Magnetorheological Damper Analysis (MR 댐퍼 해석을 위한 유압회로 모델에 대한 연구)

  • Chang, Moon Suk;Byeon, Woo Jin;Kim, Soo Tae;An, Chae Hean
    • Journal of Drive and Control
    • /
    • v.14 no.1
    • /
    • pp.8-13
    • /
    • 2017
  • This paper proposes a hydraulic circuit for a Magnetorheological (MR) damper that can be used for semi-active and active controls. Methods are presented for obtaining reliable damping force displacement and velocity data, and hysteresis loop data corresponding to applied current. In order to get reliable data, analysis using electric and electronic software, a series of tests. and comparative evaluations are required. A hydraulic circuit model is proposed that can be applied to analyze a MR damper without any assumptions where the yield stress data according to the applied current are known. Analysis results of the proposed hydraulic circuit are confirmed by experimental results within acceptable tolerance. This hydraulic circuit model can be applied to various MR dampers and systems.