• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.727-730
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• 2007

Coil inductor has been used widely as an electromagnet, because of the high magnetic filed resulting from the voltage applied to the coil. In this study the coils were used in vibration suppression as an actuator. The control system consists of a coil attached in aluminum beam and a permanent magnet set at its bottom. This actuation method is easy to be incorporated into the system and allows significant forces to be applied without contacting with the structure. Three types of coils (cylindrical type, square type, Circular sheet type) were employed in vibration suppression of cantilever beam. The positive position feedback (PPF) controller was applied to the magnet-coil actuator to suppress the first mode of vibration. Experimental results showed that the cylindrical type and square type coil made good vibration suppression efficiency under PPF controller than their eddy current damper. However, there was minimal difference for the circular sheet type coil if compared with its eddy current damper.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.540-549
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• 1999

In this paper, the vibration suppression scheme based on a model referece approach is proposed. The vibration results from the coupling of the system and its frequency are given by the mechanical factors. In the proposed scheme, a low frequency vibration mode is transferred to high one. And also its damping ratio can be increased without any mechanical redesign. Therefore, bandwidth and open loop gain of the plant are increased and the performance of the system can be improved. This paper analyzes the proposed vibration suppression scheme, which is compared with the conventional control scheme for mechanical resonance suppression. For proving the realistic validity, we apply the proposed scheme to a LOS(Line Of Sight) stabilization system which has vibration effect. Finally, the proposed scheme is verified through simulations and experiments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.592-595
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• 2004

This paper presents the feasibility of the piezoelectric shunt damping for vibration suppression of the highly rotating HDD disk-spindle system. A target vibration mode which restricts the recording density increment of the drive is determined by modal analysis of the drive, and a piezoelectric bimorph is designed to suppress the vibration level of the target mode. After deriving the generalized two-dimensional electromechanical coupling coefficient of the shunted spindle-disk system, the damping performance of the system is predicted by simulating the displacement transmissibility on the target mode. After manufacturing the proposed drive, the vibration suppression performance of the proposed methodology is experimentally evaluated in frequency domain.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.2
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• pp.119-126
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• 2022

This paper presents a method to reduce the vibration-induced noise effect of an inertial measurement device mounted on a self-driving vehicle. The inertial sensor used in the GNSS/INS integrated navigation system of a self-driving vehicle is fixed directly on the chassis of vehicle body so that its navigation output is affected by the vibration of the vehicle's engine, resulting in the degradation of the navigational performance. Therefore, these effects must be considered when mounting the inertial sensor. In order to solve this problem, this paper proposes to use an in-house manufactured vibration suppression device and analyzes its impact on reducing the vibration effect. Experimental test results in a static scenario show that the vibration-induced noise effect is more clearly observed in the lateral direction of the vehicle, but can be effectively suppressed by using the proposed vibration suppression device compared to the case without it. In addition, the dynamic positioning test scenario shows the position, speed, and posture errors are reduced to 74%, 67%, and 14% levels, respectively.

• Smart Structures and Systems
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• v.1 no.1
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• pp.13-27
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• 2005

Simultaneous precision positioning and vibration suppression of a reciprocating flexible manipulator is investigated in this paper. The flexible manipulator is driven by a multifunctional active strut with fuzzy logic controllers. The multifunctional active strut is a combination of a motor assembly and a piezoelectric stack actuator to simultaneously provide precision positioning and wide frequency bandwidth vibration suppression capabilities. First, the multifunctional active strut and the flexible manipulator are introduced, and their dynamic models are derived. A control strategy is then proposed, which includes a position controller and a vibration controller to achieve simultaneous precision positioning and vibration suppression of the flexible manipulator. Next, fuzzy logic control approach is presented to design a fuzzy logic position controller and a fuzzy logic vibration controller. Finally, experiments are conducted for the fuzzy logic controllers and the experimental results are compared with those from a PID control scheme consisting of a PID position controller and a PID vibration control. The comparison indicates that the fuzzy logic controller can easily handle the non-linearity in the strut and provide higher position accuracy and better vibration reduction with less control power consumption.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.5
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• pp.645-652
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• 2010

For free motions, vibration suppression of single flexible manipulators has been one of the hottest research topics. However, for cooperative motions of multiple flexible manipulators, a little effort has been devoted for the vibration suppression control. So, the aim of this paper is to develop a hybrid force/position control and vibration suppression control scheme for multiple cooperation flexible manipulators handling a rigid object. In order to clarify the discussion, the motions of dual-arm experimental flexible manipulator are considered. Using the developed model, we control a robotic system with hybrid position/force control scheme. Finally, Experiments are performed, and a comparison of experimental results is given to clarify the validity of our control scheme.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.189-195
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• 2000

For free motions, vibration suppression of flexible manipulators has been one of the hottest research topics. However, for constrained motions, a little effort has been devoted for vibration suppression control. Using the dependency of elastic deflections of links on contact force under static conditions, vibrations for constrained planar two-link flexible manipulators have been suppressed successfully by controlling the contact force. However, for constrained spatial multi-link flexible manipulators, the vibrations cannot be suppressed by only controlling the contact force. So, the aim of this paper is to clarify the vibration mechanism of a constrained, multi-DOF, flexible manipulator and to devise the suppression method. We apply a concise hybrid position/force control scheme to control a flexible manipulator modeled by lumped-parameter modeling method. Finally, a comparison between simulation and experimental results is presented to show the performance of our method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.41.2-41
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• 2001

A torque transmission system, which is composed of several gears and couplings, is flexible. Therefore, the torsion vibration occurs when the motor speed abruptly changes. Consequently, for Accuracy characteristic response of motor, we must suppressed vibration. Therefore, vibration suppression is very important motor control. To vibration suppression, various control method have been proposed. Specially, one method of vibration suppression used disturbance observer filter. This method is torsion torque passing disturbance observer filter. By feedback of the estimated torsion torque, the vibration can be suppressed The coefficient diagram method is used to design the filter and proportional controller.

• Journal of KSNVE
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• v.8 no.1
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• pp.171-179
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• 1998

The present paper deals with the dynamic stability and vibration suppression of a cantilevered flexible pipe having a tip mass under an internal flowing fluid. The equations of motion are derived by energy expressions using extended Hamilton's principle, and some analytical results using Galerkin's method are presented. Finally, the vibration suppression technique by means of an internal fluid flow is demonstrated experimentally.

• Structural Engineering and Mechanics
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• v.12 no.2
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• pp.135-156
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• 2001

Analytical solutions and finite element results of laminated composite plates with smart material layers embedded in them are presented in this study. The third-order plate theory of Reddy is used to study vibration suppression characteristics. The analytical solution for simply supported boundary conditions is based on the Navier solution procedure. The velocity feedback control is used. Parametric effects of the position of the smart material layers, material properties, and control parameters on the suppression time are investigated. It has been found that (a) the minimum vibration suppression time is achieved by placing the smart material layers farthest from the neutral axis, (b) using thinner smart material layers have better vibration attenuation characteristics, and, (c) the vibration suppression time is larger for a lower value of the feedback control coefficient.