• Title, Summary, Keyword: vibration control

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Optimal Vibration Control of Vehicle Engine-Body System using Haar Functions

  • Karimi Hamid Reza
    • International Journal of Control, Automation, and Systems
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    • v.4 no.6
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    • pp.714-724
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    • 2006
  • In this note a method of designing optimal vibration control based on Haar functions to control of bounce and pitch vibrations in engine-body vibration structure is presented. Utilizing properties of Haar functions, a computational method to find optimal vibration control for the engine-body system is developed. It is shown that the optimal state trajectories and optimal vibration control are calculated approximately by solving only algebraic equations instead of solving the Riccati differential equation. Simulation results are included to demonstrate the validity and applicability of the technique.

Regional Control of Vibration (진동의 영역 제어)

  • Kim, Yang-Hann;Chang, Ji-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.472-475
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    • 2008
  • Generally, a linear vibration theory regards a vibratory system as the superposition of many degrees of vibratory system. Modal analysis stems, in fact, considers the vibration system as what has input, output, and transfer function that relates the input and output. When we want to control, however, the vibratory system, we define, first, the object function that can be vibration energy of certain vibratory system. Then, we try to find the transfer function that can minimize the object function. We can readily extend this approach to control the distributed vibration system. For example, the vibrations of a vehicle, including ships and trains. In this case, we may want to minimize the vibration of the area we select. For example, minimize the vibration of the passengers' seat, but allowing the vibration of other area; for example engines and wheels. This paper introduces a general theory that can control the vibration of the selected area, which can be called as "regional control of vibration." In fact, this is the extended theory of well known sound control of "bright zone"(Choi and Kim, 2002).]. Several illustrative examples demonstrate the applicability and properties that are not available if we use modal analysis method.

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A Study on Active Vibration Isolation Using Electro-Magnetic Actuator (전자기력을 이용한 능동제진에 관한 연구)

  • 손태규;김규용;박영필
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.5
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    • pp.1169-1181
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    • 1994
  • Vibration isolation of mechanical systems, in general, is achieved through passive or active vibration isolators. Passive vibration isolator has an inherenrt performance limitation. Whereas, active vibration isolator provides significantly superior vibration-isolation performance at the cost of energy sources and sensors. Recently, in many cases, such as suspension system, precision machinery ... etc, active isolation system outweighs its limitation. Therefore, many studies, researches, and applications are carried out in this field. In this study, vibration-isolation characteristics of an active vibration control system using electromagnetic force actuator are investigated. Several control algorithms including optimal, feedforward are used for active vibration isolation. From the experimental results of each algorithm, effective control algorithms for this active vibration-isolation system are proposed.

Stochastic vibration suppression analysis of an optimal bounded controlled sandwich beam with MR visco-elastomer core

  • Ying, Z.G.;Ni, Y.Q.;Duan, Y.F.
    • Smart Structures and Systems
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    • v.19 no.1
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    • pp.21-31
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    • 2017
  • To control the stochastic vibration of a vibration-sensitive instrument supported on a beam, the beam is designed as a sandwich structure with magneto-rheological visco-elastomer (MRVE) core. The MRVE has dynamic properties such as stiffness and damping adjustable by applied magnetic fields. To achieve better vibration control effectiveness, the optimal bounded parametric control for the MRVE sandwich beam with supported mass under stochastic and deterministic support motion excitations is proposed, and the stochastic and shock vibration suppression capability of the optimally controlled beam with multi-mode coupling is studied. The dynamic behavior of MRVE core is described by the visco-elastic Kelvin-Voigt model with a controllable parameter dependent on applied magnetic fields, and the parameter is considered as an active bounded control. The partial differential equations for horizontal and vertical coupling motions of the sandwich beam are obtained and converted into the multi-mode coupling vibration equations with the bounded nonlinear parametric control according to the Galerkin method. The vibration equations and corresponding performance index construct the optimal bounded parametric control problem. Then the dynamical programming equation for the control problem is derived based on the dynamical programming principle. The optimal bounded parametric control law is obtained by solving the programming equation with the bounded control constraint. The controlled vibration responses of the MRVE sandwich beam under stochastic and shock excitations are obtained by substituting the optimal bounded control into the vibration equations and solving them. The further remarkable vibration suppression capability of the optimal bounded control compared with the passive control and the influence of the control parameters on the stochastic vibration suppression effectiveness are illustrated with numerical results. The proposed optimal bounded parametric control strategy is applicable to smart visco-elastic composite structures under deterministic and stochastic excitations for improving vibration control effectiveness.

Recent Developments in Japan Relevant to Structural Vibration Control

  • Seto, Kazuto
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.5-18
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    • 1993
  • This paper reports the recent trends in active vibration control in Japan, especially, based on papers selected in the Proceedings of First International Conference on Motion and Vibration Control (1st MOVIC) held at Yokohama, Japan on Sept.7-11, 1992. Firstly, it classifiers vibration control methods and vibration controllers, especially active dynamic absorbers which are widely used in mechanical and civil engineering. Secondly, it covers basic problems in the control of vibration of flexible structures such as formulating a reduced-order model required for designing vibration controller, proper arranging of sensors and actuators, and preventing of spillover instability. Finally, the practical use of control theories such as LQ control theory, $H^{\infty}$ control theory, neural network theory, and other topics are discussed..

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Development of the vibration control devices and the optimal base-isolation design system for Structures (구조물 진동제어장치 개발 및 최적 면진설계 시스템 개발)

  • Kim, Byung-Hyun;Chung, Jung-Hoon;Moon, Seok-Jun;Huh, Young-Cheol;Chung, Jong-Ahn
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.375-380
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    • 2004
  • Seismic Isolation and Shock/vibration Control Laboratory has performed the National Research Laboratory(NRL) project, 'Design and Application of Control Devices against Earthquake/Shock/Vibration'. In this project, the prototypes of the vibration control devices for structural control against earthquake and wind were developed and verified their performances. And also, the computer programs were developed for the seismic response analysis and the optimum design of the base-isolated structures with vibration control devices. This paper introduces the developed vibration control devices and computer programs.

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Active vibration control of multi-point mounting systems with flexible structures (유연구조물이 있는 다점지지 시스템의 능동진동제어)

  • Oh, Shi-Hwan;Park, Young-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.274-279
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    • 2000
  • Driving of the engine makes unbalance forces which induces vibration to the engine mount system. Active vibration control must be performed to reduce the vibration and the propagation of structure-born sound. In this study, the engine system is modeled as 3-dim. vibration system including flexible structures and an effective active noise control method is proposed. Also, appropriate actuator and sensor locations and types are selected. The miniature of the engine vibration system with multi-input multi-output is built and an active vibration control with multiple filtered-X LMS algorithm is applied to it. The applied control method was effective to reduce the transmitted vibration power through the rubber mount It showed the feasibility of the control of the engine vibration systems with flexible structures.

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Active Control of Multi-Mode Forced Vibration Using PZT (PZT를 이용한 다중 모드 강제 진동의 능동 제어)

  • 한상보;윤신일
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.407-412
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    • 1997
  • There has been a recent surge of research interest on the smart structure. This paper presents active vibration control scheme of multi-mode forced vibration using piezoceramic sensors/actuators. The control scheme adopted is the Positive Position Feedback control. Among various vibration control techniques, PPF control technique makes use of generalized displacement measurements to accomplish vibration suppression. Two independent controllers are implemented to control the first and the second modes of the beam under external excitation. Experimental results for various damping ratio and feedback gains of the PPF controllers are compared with respect to the control efficiency. The results indicate that steady state vibration under wideband excitation can be controlled effectively when multiple sets of PZT sensors/actuators were used with PPF control technique.

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Active Vibration Control of Multi-Mode Forced Vibration Using PPF Control Technique (PPF 제어기법을 이용한 다중 모드 강제 진동의 능동 진동 제어)

  • 한상보;곽문규;윤신일
    • Journal of KSNVE
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    • v.7 no.6
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    • pp.1007-1013
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    • 1997
  • This paper presents active vibration control scheme of multi-mode forced vibration using piezocetamic sensors and actuators. The control scheme adopted is the Positive Position Feedback (PPF) control. Among various vibration control techniques. PPF control technique makes use of generalized displacement measurements to accomplish the vibration suppression. Two independent controllers are implemented to control the first and the second modes of the beam under external excitation. Experimental results for various damping ratios and feedback gains of the PPF controllers are compared with respect to the contorl efficiency. The results indicate that steady state vibration under wide band excitation can be controlled effectively when multiple sets of PZT sensors and actuators were used with PPF control technique.

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Vibration Suppression Control for a Twin-Drive Geared Mechanical System with Backlash: Effects of Model-Based Control

  • Itoh, Masahiko
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1392-1397
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    • 2003
  • This paper deals with a control technique of eliminating the transient vibration of a twin-drive geared mechanical system. This technique is based on a model-based control in order to establish the damping effect at the driven machine part. The control model is composed of reduced-order electrical and mechanical parts. This control model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically and it is added to the velocity command to suppress the transient vibration generated at the load. This control technique is applied to a twin-drive geared system with backlash. In the previous work, the performance of this control method is examined by simulations. In this paper, the effectiveness of this control technique is verified by experiments. The settling time of the residual vibration generated at the loading inertia can be shortened down to about 1/2 of the uncompensated vibration level.

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