• Title/Summary/Keyword: Damper Control System

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Control of Smart Base-isolated Benchmark Building using Fuzzy Supervisory Control (퍼지관리제어기법을 이용한 스마트 면진 벤치마크 건물의 제어)

  • Kim, Hyun-Su;Roschke P. N.
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.4 s.44
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    • pp.55-66
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    • 2005
  • The effectiveness of fuzzy supervisory control technique for the control of seismic responses of smart base isolation system is investigated in this study. To this end, first generation base isolated building benchmark problem is employed for the numerical simulation. The benchmark structure under consideration is an eight-story base isolated building having irregular plan and is equipped with low-damping elastometric bearings and magnetorheological (MR) dampers for seismic protection. Lower level fuzzy logic controllers (FLC) for far-fault or near-fault earthquakes are developed in order to effectively control base isolated building using multi-objective genetic algorithm. Four objectives, i.e. reduction of peak structural acceleration, peak base drift, RMS structural acceleration and RMS base drift, are used in multi-objective optimization process. When earthquakes are applied to benchmark building, each of low level FLCs provides different command voltage and supervisory fuzzy controller combines two command voltages io one based on fuzzy inference system in real time. Results from the numerical simulations demonstrate that base drift as well as superstructure responses can be effectively reduced using the proposed supervisory fuzzy control technique.

Optimal variables of TMDs for multi-mode buffeting control of long-span bridges

  • Chen, S.R.;Cai, C.S.;Gu, M.;Chang, C.C.
    • Wind and Structures
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    • v.6 no.5
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    • pp.387-402
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    • 2003
  • In the past decades, much effort has been made towards the study of single-mode-based vibration controls with dynamic energy absorbers such as single or multiple Tuned Mass Dampers(TMDs). With the increase of bridge span length and the tendency of the bridge cross-section being more slender and streamlined, multi-mode coupled vibrations as well as their controls have become very important for large bridges susceptible to strong winds. As a simple but effective device, the TMD system especially the semi-active one has become a promising option for such coupled vibration controls. However, despite various studies of optimal controls of single-mode-based vibrations with TMDs, research on the corresponding controls of the multi-mode coupled vibrations is very rare so far. For the development of a semi-active control strategy to suppress the multi-mode coupled vibrations, a comprehensive parametric analysis on the optimal variables of this control is substantial. In the present study, a multi-mode control strategy named "three-row" TMD system is discussed and the general numerical equations are developed at first. Then a parametric study on the optimal control variables for the "three-row" TMD system is conducted for a prototype Humen Suspension Bridge, through which some useful information and a better understanding of the optimal control variables to suppress the coupled vibrations are obtained. This information lays a foundation for the design of semi-active control.

Evaluation on Vibration Control Performance of Interaction Vibration Control System using Friction Damper (마찰댐퍼를 이용한 연결제진구조물의 제진성능곡선)

  • Kim, Hyun-Soo;Choi, Jae-Hyouk
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2009.04a
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    • pp.458-461
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    • 2009
  • 본 논문에서는 2개의 구조물이 마찰댐퍼로 연결된 연결제진구조물에 대한 지진응답해석을 실시하였다. 연결제진구조물의 지진시의 제진효과를 파악하기 위하여 마찰댐퍼의 복원력특성을 완전탄소성형으로 설정하고 두 구조물의 고유주기 및 연결강성의 변화에 따른 각 지진파별 시간이력지진응답해석을 실시하였다. 또한, 응답해석결과를 바탕으로 마찰댐퍼의 특성지표(연결강성배율 $\alpha$, 항복내력비 $\beta$)를 결정하는 제진성능곡선을 제안하였다. 제진성능곡선을 통한 마찰댐퍼의 특성지표에 근거하여 연결제진구조물에 마찰댐퍼를 효율적으로 사용할 수 있는 최적의 마찰댐퍼량을 결정 할 수 있는 자료를 제시하였다.

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New Algorithm for Recursive Estimation in Linear Discrete-Time Systems with Unknown Parameters

  • Shin Vladimir;Ahn Jun-Il;Kim Du-Yong
    • International Journal of Control, Automation, and Systems
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    • v.4 no.4
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    • pp.456-465
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    • 2006
  • The problem of recursive filtering far linear discrete-time systems with uncertainties is considered. A new suboptimal filtering algorithm is herein proposed. It is based on the fusion formula, which represents an optimal mean-square linear combination of local Kalman estimates with weights depending on cross-covariances between local filtering errors. In contrast to the optimal weights, the suboptimal weights do not depend on current measurements, and thus the proposed algorithm can easily be implemented in real-time. High accuracy and efficiency of the suboptimal filtering algorithm are demonstrated on the following examples: damper harmonic oscillator motion and vehicle motion constrained to a plane.

Performance of Seismic Protective Systems for Super-Tall Buildings and Their Contents

  • Kasai, Kazuhiko
    • International Journal of High-Rise Buildings
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    • v.5 no.3
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    • pp.155-165
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    • 2016
  • A much higher level of seismic performance is needed for supertall buildings due to increased demands for their functional continuities and the recognized needs for their continuing emergence in metropolitan areas. This paper analyzes, compares, and contrasts responses recorded during the 2011 Tohoku-oki Earthquake of different supertall buildings featuring conventional and vibration-controlled engineering systems. The superior performance and advantage of the latter are pointed out, and the typical dynamic properties, response characteristics, and effects on the secondary system are discussed. Ongoing efforts to enhance vibration control performance are described, covering the development of specifications, use of performance curves and targeted displacement design, and methods to find appropriate locations of damper installation resulting in a minimized amount of dampers.

Experimental Study on Stability of Robust Saturation Controller (강인 포화 제어기의 안정성에 관한 실험적 연구)

  • Lim, Chae-Wook;Moon, Seok-Jun;Park, Youngjin;Park, Yun-Sik
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.2 s.107
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    • pp.207-213
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    • 2006
  • In our previous research, we proposed a robust saturation controller which involves both control input saturation and structured real parameter uncertainties. This controller can analytically prescribed the upper and lower bounds of parameter uncertainties, and guarantee the closed-loop robust stability of the system in the presence of actuator's saturation. And the availability and the effectiveness of the proposed robust saturation controller were verified through numerical simulations. In this paper, we verify the robust stability of this controller through experimental tests. Expecially, we show unstable cases of other controllers in comparison with this controller. Experimental tests are carried out in the laboratory using a two-story test structure with a hydraulic-type active mass damper.

Fuzzy-sliding mode control of a full car semi-active suspension systems with MR dampers

  • Zheng, L.;Li, Y.N.;Baz, A.
    • Smart Structures and Systems
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    • v.5 no.3
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    • pp.261-277
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    • 2009
  • A fuzzy-sliding mode controller is presented to control the dynamics of semi-active suspension systems of vehicles using magneto-rheological (MR) fluid dampers. A full car model is used to design and evaluate the performance of the proposed semi-active controlled suspension system. Four mixed mode MR dampers are designed, manufactured, and integrated with four independent sliding mode controllers. The siding mode controller is designed to decrease the energy consumption and maintain robustness. In order to overcome the chattering of the sliding mode controllers, a fuzzy logic control strategy is merged into the sliding mode controller. The proposed fuzzy-sliding mode controller is designed and fabricated. The performance of the semi-active suspensions is evaluated in both the time and frequency domains. The obtained results demonstrate that the proposed fuzzy-sliding mode controller can effectively suppress the vibration of vehicles and improve their ride comfort and handling stability. Furthermore, it is shown that the "chattering" of the sliding mode controller is smoothed when it is integrated with a fuzzy logic control strategy. Although the cost function of the fuzzy-sliding mode control is a slightly higher than that of a classical LQR controller, the control effectiveness and robustness are enhanced considerably.

A Study on Vibration Control of Port Structure using Immunized PID Controller (Immunized PID 제어기를 이용한 항만 구조물의 진동제어에 관한 연구)

  • Lee, Young-Jin;Lee, Kwon-Soon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.399-404
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    • 2005
  • In this paper, An immunized PID(I-PID) controller based on cell mediated immune response is proposed to improve the control performance of the controller with PID scheme. And it is applied to the vibration of the building structure in the port with active damper systems. The immune system of organism in the real body regulates the antibody and T-cells to protect the attack from the foreign materials which are virus, germ cell, and other antigens. It has similar characteristics that are the adaptation and robustness to overcome disturbances and to control the plant of engineering application. At firstly, we build a model of the T-cell regulated immune response mechanism. We have also designed an I-PID controller focusing on the T-cell regulated immune response of biological immune system. Finally, we show that some computer simulations of the vibraton control for the building structure system with wind force excitation. These results for the proposed method also show that is has performance than other conventional controller design method.

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Vibration Control Performance Evaluation of Smart TMD for a Tilted Diagrid Tall Building (경사진 다이어그리드 비정형 초고층 건물에 대한 스마트 TMD의 제진성능평가)

  • Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.11 no.4
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    • pp.79-88
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    • 2011
  • Recently, complex-shaped tall buildings represented by 3T(Twisted, Tapered, Tilted) are planed largely. A diagrid structural system is one of the most widely used structural system for complex-shaped tall buildings because of its structural efficiency and formativeness. Plans for tilted tall buildings are largely presented because of beauty of a sculpture and many of buildings use diagrid structural systems. Lateral displacements of tilted tall buildings are induced by not only lateral loads but also self weight. Therefore, reduction of lateral responses of tilted tall buildings is as important as typical tall buildings. In this study, a smart TMD is introduced to reduce seismic responses of tilted diagrid tall buildings and its control performance is evaluated. MR damper is employed for the smart TMD and ground-hook controller is used as a control algorithm for the smart TMD. 100-story tall building is used as an example structure. Control performances of uncontrolled case, controlled case with TMD and controlled case with smart TMD are compared and investigated. Numerical simulation has shown that smart TMD presented good control performance for displacement response but acceleration response was not controlled well.

An Adaptive UPFC Based S tabilizer forDamping of Low Frequency Oscillation

  • Banaei, M.R.;Hashemi, A.
    • Journal of Electrical Engineering and Technology
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    • v.5 no.2
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    • pp.197-208
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    • 2010
  • Unified power flow controller (UPFC) is the most reliable device in the FACTS concept. It has the ability to adjust all three control parameters effective in power flow and voltage stability. In this paper, a linearized model of a power system installed with a UPFC has been presented. UPFC has four control loops that by adding an extra signal to one of them, increases dynamic stability and load angle oscillations are damped. In this paper, after open loop eigenvalue (electro mechanical mode) calculations, state-space equations have been used to design damping controller and it has been considered to influence active and reactive power flow durations as the input of damping controller, in addition to the common speed duration of synchronous generators as input damper signal. To increase stability, further Lead-Lag and LQR controllers, a novel on-line adaptive controller has been used analytically to identify power system parameters. Closed-loop calculations of the electro mechanical mode verify the improvement of system pole placement after controller designing. Suitable operation of adaptive controller to decrease rotor speed oscillations against input mechanical torque disturbances is confirmed by the simulation results.