scholarly journals Active vibration suppression of a beam using piezoeffect

2019 ◽  
Vol 97 ◽  
pp. 03024
Author(s):  
Nelly Rogacheva
Keyword(s):  
Vibration Isolation ◽  
Vibration Suppression ◽  
External Energy ◽  
Active Systems ◽  
Vibration Isolators ◽  
Active Vibration Suppression ◽  
Passive Vibration Isolation ◽  
Protected Object ◽  
Active Vibration ◽  
Isolation Systems

Operation of structures and equipment in dynamic conditions led to the problems of vibration isolation and vibration suppression. For vibration isolation and vibration suppression passive, active systems and their combinations are used. Passive vibration isolation usually consists in the fact that the protected object relies on extremely dimensional springs and vibration isolators. Vibration isolation systems containing only passive elastic and damping elements are called passive. Active vibration isolation and vibration damping systems use external energy sources. These are pneumatic, hydropneumatic and hydromechanical devices. Recently, electro-elastic and magneto-elastic systems [1], [2] began to be used for vibration isolation and active vibration suppression. As a rule, the analysis of the work of such systems consists in the development of an experimental layout and a schematic diagram. In this paper, a mathematically based model is used to solve the problem in question. The calculations are performed and the results are presented in the form of graphs.

Application of Compliant Mechanisms to Active Vibration Isolation Systems

2004 ◽  
Author(s):  
Tanakorn Tantanawat ◽  
Zhe Li ◽  
Sridhar Kota
Keyword(s):  
Vibration Isolation ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Vibration Isolator ◽  
External Energy ◽  
Low Frequencies ◽  
Output Amplitude ◽  
Active Vibration ◽  
Isolation Systems ◽  
Active Vibration Isolation

Compliant mechanisms have been designed for various types of applications to transmit desired forces and motions. In this paper, we explore an application of compliant mechanisms for active vibration isolation systems. For this type of application, an actuator and a compliant mechanism are used to cancel undesired disturbance, resulting in attenuated output amplitude. An actuator provides external energy to the system while a compliant mechanism functions as a transmission controlling the amount of displacement transmitted from the actuator to the payload to be isolated. This paper illustrates, based on preliminary results of finite element analyses (FEA), that a compliant mechanism equipped with an actuator can be used as an active vibration isolator to effectively cancel a known sinusoidal displacement disturbance at low frequencies by using a feedforward disturbance compensation control. The nonlinear FEA shows that a sinusoidal displacement disturbance of 6.0 mm amplitude is reduced by 95% at 3.9 Hz and 91% at 35.1 Hz with a sinusoidal displacement controlled input of 0.73 mm amplitude.

Retrofitting Active Control into Passive Vibration Isolation Systems

1998 ◽  
Vol 120 (1) ◽  
pp. 104-110 ◽  
Author(s):  
D. Margolis
Keyword(s):  
Vibration Isolation ◽  
Vibrational Energy ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Active System ◽  
External Disturbances ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Excellent Control ◽  
Isolation Systems

Active vibration control uses sensing and power actuators to attenuate vibrational energy due to external disturbances. Many of these systems are retrofitted into already existing passive ones. As a result allowable relative motions are prescribed, and this influences the performance of the active system. This paper exposes these limitations and shows realistic expectations for two excellent control strategies.

Active and Semi-Active Vibration Isolation

1995 ◽  
Vol 117 (B) ◽  
pp. 177-185 ◽  
Author(s):  
D. Karnopp
Keyword(s):  
Vibration Isolation ◽  
Theoretical Concepts ◽  
Active Systems ◽  
Suspension Systems ◽  
Manufacturing Operations ◽  
Active Vibration ◽  
Isolation Systems ◽  
The Many ◽  
Active Damper ◽  
Signal Processors

In the five decades since the founding of the ASME Design Engineering Division, the important problem of vibration isolation has been attacked first through the design of passive spring-damper suspensions and later by the use of active and semi-active elements. This paper reviews the historical development of theoretical concepts necessary for the design of isolation systems and indicates how control theory began to influence vibration isolation in the last half of this period. Practical active and semi-active suspensions have only recently become possible with the advent of powerful but relatively inexpensive signal processors. To illustrate these developments for engineers who have not been intimately involved with active systems, only simple vibrational system models will be discussed, although some modern hardware will be shown which is now being applied to complex systems. Instead of attempting to review the many theoretical concepts which have been proposed for active systems, this article will focus on a relatively simple idea with which the author has been associated over the past thirty years; namely the “skyhook” damper. This idea came through purely theoretical studies but is now used in combination with other concepts in production suspension systems. Two quite different application areas will be discussed. The first involves stable platforms to provide extreme isolation for delicate manufacturing operations against seismic inputs and the second involves automotive suspensions. Although similar concepts are found in these two application areas, the widely varying requirements result in very different suspension hardware. The special case of the semi-active damper, which requires very little control power and is presently reaching production, will also be discussed.

Dynamics Enhancements of Advanced LIGO Multi-Stage Active Vibration Isolators and Related Control Performance Improvement

2012 ◽  
Author(s):  
Fabrice Matichard ◽  
Ken Mason ◽  
Richard Mittleman ◽  
Brian Lantz ◽  
Ben Abbott ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Experimental Results ◽  
Dynamical Response ◽  
Control Performance ◽  
Vibration Isolators ◽  
Multi Stage ◽  
Final Design ◽  
Active Vibration ◽  
And Performance ◽  
Isolation Systems

The control bandwidth and performance of active vibration isolation systems are usually directly related to the system dynamic characteristics. In this paper, we present results from a 4 years study carried out to improve the dynamical response and control performance on the two-stage isolator designed for Advanced LIGO detectors. The paper will focus on the platform’s first stage to illustrate prototyping, optimization, final design and the experimental results obtained during this program. The system concept, architecture and prototype will be presented. The factors initially limiting the prototype’s performance will be analyzed. Solutions based on sensors relocation, payload reduction, structural stiffening and passive techniques to damp the residual high frequency flexible modes will be presented. Experimental results obtained with the prototype will be compared with the system’s final version. The series of improvement obtained help not only to increase the system’s bandwidth, robustness and performance but also to simplify and speed up the control commissioning, which is very important for the Advanced LIGO project that will be using 5 of these platforms in each of its 3 detectors.

Active and Semi-Active Vibration Isolation

1995 ◽  
Vol 117 (B) ◽  
pp. 177-185 ◽  
Author(s):  
D. Karnopp
Keyword(s):  
Vibration Isolation ◽  
Theoretical Concepts ◽  
Active Systems ◽  
Suspension Systems ◽  
Manufacturing Operations ◽  
Active Vibration ◽  
Isolation Systems ◽  
The Many ◽  
Active Damper ◽  
Signal Processors

In the five decades since the founding of the ASME Design Engineering Division, the important problem of vibration isolation has been attacked first through the design of passive spring-damper suspensions and later by the use of active and semi-active elements. This paper reviews the historical development of theoretical concepts necessary for the design of isolation systems and indicates how control theory began to influence vibration isolation in the last half of this period. Practical active and semi-active suspensions have only recently become possible with the advent of powerful but relatively inexpensive signal processors. To illustrate these developments for engineers who have not been intimately involved with active systems, only simple vibrational system models will be discussed, although some modern hardware will be shown which is now being applied to complex systems. Instead of attempting to review the many theoretical concepts which have been proposed for active systems, this article will focus on a relatively simple idea with which the author has been associated over the past thirty years; namely the “skyhook” damper. This idea came through purely theoretical studies but is now used in combination with other concepts in production suspension systems. Two quite different application areas will be discussed. The first involves stable platforms to provide extreme isolation for delicate manufacturing operations against seismic inputs and the second involves automotive suspensions. Although similar concepts are found in these two application areas, the widely varying requirements result in very different suspension hardware. The special case of the semi-active damper, which requires very little control power and is presently reaching production, will also be discussed.

scholarly journals Tilt Active Vibration Isolation Using Vertical Pendulum and Piezoelectric Transducer with Parallel Controller

2021 ◽  
Vol 11 (10) ◽  
pp. 4526
Author(s):  
Lihua Wu ◽  
Yu Huang ◽  
Dequan Li
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Isolation ◽  
Vertical Vibration ◽  
Open Loop ◽  
Negative Effects ◽  
Voltage Controller ◽  
Hysteresis Nonlinearity ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

Tilt vibrations inevitably have negative effects on some precise engineering even after applying horizontal and vertical vibration isolations. It is difficult to adopt a traditional passive vibration isolation (PVI) scheme to realize tilt vibration isolation. In this paper, we present and develop a tilt active vibration isolation (AVI) device using a vertical pendulum (VP) tiltmeter and a piezoelectric transducer (PZT). The potential resolution of the VP is dependent on the mechanical thermal noise in the frequency bandwidth of about 0.0265 nrad, which need not be considered because it is far below the ground tilt of the laboratory. The tilt sensitivity of the device in an open-loop mode, investigated experimentally using a voltage controller, is found to be (1.63±0.11)×105 V/rad. To compensate for the hysteresis nonlinearity of the PZT, we experimentally established the multi-loop mathematical model of hysteresis, and designed a parallel controller consisting of both a hysteresis inverse model predictor and a digital proportional–integral–differential (PID) adjuster. Finally, the response of the device working in close-loop mode to the tilt vibration was tested experimentally, and the tilt AVI device showed a good vibration isolation performance, which can remarkably reduce the tilt vibration, for example, from 6.0131 μrad to below 0.0103 μrad.

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