Theoretical and Experimental Results on Active Vibration Dampers

1962 ◽  
Vol 34 (12) ◽  
pp. 1976-1976
Author(s):  
Thomas H. Rockwell ◽  
James M. Lawther
Keyword(s):  
Experimental Results ◽  
Active Vibration ◽  
Vibration Dampers

scholarly journals Performance of a Suspension Bridge with Active Vibration Dampers

2018 ◽  
Vol 196 ◽  
pp. 01017
Author(s):  
Anatolij Konovalov ◽  
Marina Pustovalova
Keyword(s):  
Cross Sections ◽  
Dynamic Properties ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Initial Model ◽  
Strain Behavior ◽  
Pedestrian Bridges ◽  
Active Vibration ◽  
Active Damper ◽  
Vibration Dampers

Suspended structures that are used extensively in construction of motorway and pedestrian bridges allow bridging wide spans without having to install intermediate supports. Being less stiff in comparison to girder and arch bridges, suspension bridges require their dynamic properties to be controlled [1, 2]. This is a vital task when it comes to suspension bridges. Several engineering arrangements are available to control the dynamic properties of the structures [3]. This paper addresses the use of active dampers [4] installed on the tops of the towers as the means to control vibrations of a suspension bridge. To this end, a planar 3D model of suspension bridge was built using ANSYS software. The authors compared stress-strain behavior and dynamic properties of the models with and without active vibration dampers. In contrast to the initial model, the model of a bridge equipped with active dampers exhibits less displacement in all cross-sections. Thus, the displacements are reduced 1.7 times in the middle of the central span of suspended stiffening truss; 2.7 times in the middle of the end span; and displacements of the top of the bridge tower are 1.6 times less. The modal analysis has shown that in the model with active dampers the frequency of transverse vibrations at the tower tops has increased 1.9 times, while vertical vibrations have increased within 23%. Under maximum applied overpressure in the active damper, torsional vibrations of the structure have increased 2.4 times as compared to the initial model. The results obtained by the authors allow for the conclusion that active dampers are useful tools for controlling the dynamic properties of a suspension bridge.

Sloshing Damping Control in a Cylindrical Container on a Wheeled Mobile Robot Using Dual-Swing Active-Vibration Reduction

2009 ◽  
Vol 21 (5) ◽  
pp. 642-646 ◽  
Author(s):  
Masafumi Hamaguchi ◽  
◽  
Takao Taniguchi
Keyword(s):  
Kalman Filter ◽  
Mobile Robot ◽  
Vibration Reduction ◽  
Wheeled Mobile Robot ◽  
Experimental Results ◽  
Cylindrical Container ◽  
Damping Control ◽  
Direction Of Movement ◽  
Active Vibration ◽  
Servo Controller

Damping control we propose for sloshing in cylindrical containers carried by a wheeled mobile robot enables the container to tilt independently in the direction of movement and orthogonally through the use of a dual-swing active-vibration reducer. The robot follows a curved sloping path. Sloshing generated by robot movement is damped by the vibration reducer, which keeps the container level on a slope. Vibration reduction is managed by an optimal servo controller having a Kalman filter. Experimental results demonstrate our damping control proposal's usefulness and feasibility.

Two-Level Control Structure of Magnetic Bearings

1993 ◽  
Vol 5 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Nobuyoshi Taguchi ◽  
◽  
Takakazu Ishimatsu ◽  
Takashi Shimomachi ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Structure ◽  
Active Vibration Control ◽  
Experimental Results ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Level Control ◽  
Whirling Motion ◽  
Active Vibration

Active magnetic bearings have several advantages over conventional mechanical and fluid bearings. However, when the magnetic bearings are used at high rotational speeds, whirling motions and vibrations synchronized with the rotation of the rotor should be considered. In order to suppress these unfavorable vibrations of rotor which is supported by magnetic bearings, we have developed an active vibration control system with a two-level control structure. Experimental results show that our active bearings system effectively suppresses the whirling motion.

Design of an Active-Vibration System Based on Sky-Hook Damper and Impedance Control

2013 ◽  
Vol 416-417 ◽  
pp. 860-865
Author(s):  
Wu Sung Yao ◽  
Po Wen Hsueh ◽  
Mi Ching Tsai
Keyword(s):  
Impedance Control ◽  
Low Frequency ◽  
Control Design ◽  
Experimental Results ◽  
Vibration System ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Low Frequency Vibration ◽  
Model Reference Control ◽  
Active Vibration

This paper investigates an active anti-vibration system, and the isolation of low-frequency vibration is studied. A model reference control of the anti-vibration system with a sky-hook damper and impedance control is analyzed. An illustrated example of a single-degree-of-freedom anti-vibration system driven by a tubular linear servomotor is given to verify the performance of the proposed control design. Experimental results are given to show that the peak resonance value of 0dB within a frequency of 10Hz can be achieved successively.

scholarly journals Simultaneous active vibration control and health monitoring of structures. Experimental results

2010 ◽  
Vol 2 (2) ◽  
pp. 118-127 ◽  
Author(s):  
URSU Ioan ◽  
◽  
TECUCEANU George ◽  
TOADER Adrian ◽  
BERAR Vladimir
Keyword(s):  
Vibration Control ◽  
Health Monitoring ◽  
Active Vibration Control ◽  
Experimental Results ◽  
Active Vibration

Numerical and Experimental Investigation of a Single-Axis Parallel Active Vibration Mount for Helicopter Seats Using Vibration Standards

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Amin Fereidooni ◽  
Silas Graham ◽  
Eric Chen ◽  
Viresh Wickramasinghe
Keyword(s):  
Vibration Isolation ◽  
Experimental Results ◽  
Least Mean Square ◽  
Axis Parallel ◽  
Active Vibration ◽  
Iso 2631 ◽  
The Given ◽  
Nonlinear Numerical Model ◽  
Good Agreement ◽  
Helicopter Vibration

Abstract This paper presents the experimental and numerical investigation of a single-axis replicate of a patented multi-axis active vibration isolation seat mount. Following the design of the multi-axis system, this single axis vibration isolation mount uses a flexible elastomer support placed in parallel with an electromagnetic actuator. This mount is designed to reduce the N/rev harmonic vibration of a helicopter using a filtered-X least mean square (FXLMS)-based controller. To improve the efficiency of the FXLMS controller for this application, the ISO-2631-1 Wk filter is added. Employing this modified controller, the experimental setup is tested using a payload mass representative of a 95th percentile pilot. The experimental results confirm the effectiveness of the proposed design in canceling the unwanted helicopter vibration, where the active mount effectively reduces the vibration representative of a Bell-412 helicopter by 69.37% (−10.28 dB, g-rms). In order to develop a better understanding of the problem, the system is also modeled from first principles in simulink. The comparison between the nonlinear numerical model and the experimental results demonstrates a good agreement between the two approaches. Moreover, it is shown that the addition of the ISO-2631-1 Wk filter improves the transient performance of the FXLMS controller for the given helicopter vibration profile.

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