Modeling of Beam as Control Plane for a Vibration Control System

2008 ◽  
Vol 144 ◽  
pp. 59-64 ◽  
Author(s):  
Zdzisław Gosiewski ◽  
Andrzej Piotr Koszewnik
Keyword(s):  
Open Loop ◽  
Optimal Location ◽  
Mode Shapes ◽  
Open Loop System ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
Frequency Changes ◽  
Control Forces ◽  
Optimal Localization ◽  
Selection Of

An active vibration damping system with the use of piezoelements fixed to the structure is presented in the paper. The optimal location of the piezo-stripes on the structure is calculated for given cost functions. Coefficient correlations between control forces, strains, mode shapes, frequency changes, modal masses and modal stiffness are analyzed in order to find simpler method for calculation of the quasi-optimal localization of piezo-sensors and piezo-actuators. Reduced model of the open-loop system was identified and the simulations were carried out in order to find the best controller to reduce the amplitude of vibrations. The correctness of the selection of the controller was verified and investigated experimentally.

Eigenstructure Calculation for Mixed Vibratory Systems Composed of a Continuous Beam and Concentrated Actuators

2001 ◽  
Author(s):  
Michael J. Panza
Keyword(s):  
Active Vibration Control ◽  
Open Loop ◽  
Mode Shapes ◽  
Mixed System ◽  
Continuous Beam ◽  
Actuator Dynamics ◽  
Asymmetric System ◽  
Lumped Element ◽  
Active Vibration ◽  
Parameter Values

Abstract A calculation of the eigenstructure for mixed vibratory systems composed of a continuous beam and concentrated actuators is presented. The combined distributed and lumped element systems include actuators for active vibration control. The focus of this paper is on open loop models where with zero voltage input to the actuators. The continuous beam is isolated and discretized via modal analysis and combined with the actuator dynamics to form an asymmetric system. The resulting system is cast into a generalized nondimensional form suitable for studying system behavior for a broad range of system parameters. The solution is expressed as a series using the isolated beam mode eigenfunctions as a basis. The coefficients in the series are obtained from the complex eigensolution of the asymmetric system. Two examples are used to show a comparison of the complex mixed system and real isolated beam natural frequencies and mode shapes. The effect of beam and actuator parameter values are investigated via a key dimensionless parameter.

Frequency Domain Identification of the Active Beam Model for the Vibration Control System

2009 ◽  
Vol 147-149 ◽  
pp. 320-325 ◽  
Author(s):  
Zdzisław Gosiewski ◽  
Andrzej Piotr Koszewnik
Keyword(s):  
Frequency Domain ◽  
Open Loop ◽  
Least Square ◽  
Beam Model ◽  
Domain Identification ◽  
Resonance Frequencies ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
Band Pass ◽  
Bode Plots

An identification procedure of the active vibration damping system with the piezo-elements glued to the structure is presented in the paper. Such identification can be carried out in analytical way (Guyan reduction) by using of low-band pass amplifiers. First, we have identified the open loop system in the frequency domain by using experimental setup with real amplifier and beam equipped in piezo-strips working as actuators and sensor, respectively. For the frequency range 1 Hz to 400 Hz we have obtained Bode plots with helped of Dynamic Signal Analyzer which were base to further calculations. Second, mathematical model have been adjusted to the experimental results by the least square sum approach and also by the consideration of a system which was modeled by finite elements. A three first resonance frequencies and three first anti-resonance frequencies have obtained.

Modular Add-On System for Vibration Control in Gantry Milling Machines

2005 ◽  
Author(s):  
Michael F. Za¨h ◽  
Haitham Rashidy ◽  
Florian Gra¨tz
Keyword(s):  
Controller Design ◽  
Fem Analysis ◽  
Mode Shapes ◽  
Medium Size ◽  
Characteristic Mode ◽  
Milling Machines ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
Machining Characteristics ◽  
Machine Structure

On the part of the manufacturer as well as the user, the notion of modular configurable machine tools gains increasing applause. It is almost evident that the need not only for configurable machine structures but also machining characteristics will be an incisive feature of the future machine tool. In this paper a concept for a modular add-on solution for active vibration damping of characteristic mode shapes of a three-axis milling machine is introduced. Although the developed concept was tailored to a specific case, it is generally valid for small to medium size gantry style machines. Furthermore, the paper discusses the realization of the concept and the actuator integration into the machine structure. Also, a pragmatic controller design is proposed using a modal formulation of the machine dynamics. The results of the FEM analysis and simulation will be presented. Experimental validation of the system is underway at the time and is not included in the paper. A major advantage of the presented study is its suitability for direct application in the industry.

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.

Model to assess the selection of the optimal location for a restaurant, a quantitative approach. Case study: Theme restaurants in Cancun, Mexico

2021 ◽  
pp. 1-44
Author(s):  
Mauro Felipe Berumen Calderón ◽  
Damayanti Estolano Cristerna ◽  
Angelica Selene Sterling Zozoaga ◽  
Andreé Ricardo Berumen Calderón
Keyword(s):  
Optimal Location ◽  
Quantitative Approach ◽  
Selection Of

Selection of Component Modes for Craig-Bampton Substructure Representations

1996 ◽  
Vol 118 (2) ◽  
pp. 264-270 ◽  
Author(s):  
D. C. Kammer ◽  
M. J. Triller
Keyword(s):  
Efficient Method ◽  
Singular Values ◽  
General Purpose ◽  
Mode Shapes ◽  
Frequency Range ◽  
Reduced Representation ◽  
Absolute Measure ◽  
Fixed Interface ◽  
Interface Mode ◽  
Selection Of

Three measures of modal dynamic importance are studied for the purpose of ranking Craig-Bampton substructure fixed interface mode shapes based upon their contribution to forces at the substructure interface, modal velocity, or modal displacement. These measures can be employed to identify mode shapes which are dynamically important and thus should be retained in a reduced analytical representation, or identified during a modal survey of the substructure. The first method considered. Effective Interface Mass, has been studied previously. However, new results are presented showing the relation between Effective Interface Mass and a commonly used control dynamics measure of modal importance called approximate balanced singular values. In contrast to the general case of approximate balanced singular values, Effective Interface Mass always gives an absolute measure of the dynamic importance of mode shapes. The EIM method is extended to consider modal velocity and modal displacement outputs. All three measures are applied to a simple substructure called the General Purpose Spacecraft. It is shown that each of these measures provides an efficient method for ranking the dynamic importance of Craig-Bampton fixed interface modes such that a reduced representation will accurately reproduce the substructure’s response in the frequency range of interest.

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