A Mechanical Approach to the Design of Independent Modal Space Control for Vibration Suppression

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
S. Cinquemani ◽  
F. Resta
Keyword(s):  
Vibration Suppression ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Flexible System ◽  
Damping Matrix ◽  
Modal Damping ◽  
Active Vibration ◽  
The Stability ◽  
Modal Space ◽  
Modal Controller

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, improve the dynamic performance of the system, and increase its fatigue strength. A way to reach this goal is to increase the system damping, preferably without changing its natural frequencies and vibration modes. In the past decades this has been achieved by developing the well-known independent modal space control (IMSC) technique. The paper describes a new approach to the synthesis of a modal controller to suppress vibrations in structures. It turns from the traditional formulation of the problem and it demonstrates how the performance of the controller can be evaluated through the analysis of the modal damping matrix of the controlled system. The ability to easily manage this information allows us to synthesize an efficient modal controller. Furthermore, it enables us to easily evaluate the stability of the control, the effects of spillover, and the consequent effectiveness in reducing vibration. Theoretical aspects are supported by experimental applications on a large flexible system.

Vibration Reduction in Large Flexible Systems Through Independent Modal Control

2011 ◽  
Author(s):  
Francesco Braghin ◽  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Flexible System ◽  
Damping Matrix ◽  
Modal Damping ◽  
Active Vibration ◽  
The Stability ◽  
Modal Controller

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. The paper introduces a new approach to the synthesis of a modal controller to suppress vibrations in structures: it turns from the traditional formulation of the problem showing how the performance of the designed controller can be evaluated through the analysis of the resulting modal damping matrix of the controlled system. Such analysis allows to evaluate spillover effects, due to the presence of un-modeled modes, the stability of the control and the consequent effectiveness in reducing vibration. The ability to easily manage this information allows the synthesis of an efficient modal controller. Theoretical aspects are supported by experimental applications on a large flexible system.

Optimal Research of Actuator Placement for Piezoelectric Smart Structure

2009 ◽  
Vol 419-420 ◽  
pp. 173-176
Author(s):  
Wei Yuan Wang ◽  
Kai Xue ◽  
Dong Yan Shi
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Active Vibration Control ◽  
Element Model ◽  
Smart Structure ◽  
Optimal Placement ◽  
Optimal Method ◽  
Modal Damping ◽  
Active Vibration ◽  
Modal Space

The purpose of this paper is to investigate the optimal placement of piezoelectric actuator for active vibration control of smart structure. The structures can be described in the modal space based on the independent modal space control method and dynamic equations derived from finite element model. The modal damping ratios are derived from modal equations and an optimal target is given by maximizing the modal damping ratios. Accumulation method is adopted to the optimization calculation. Simulations are carried out for active vibration control of a conical shell with distributed piezoelectric actuators. Control effects proved the validity of the optimal method above by compared with the non-optimal results. The optimal method in this paper gives a useful guide for quantity optimization of actuators to piezoelectric structures.

Actuator Placement for Active Vibration Control Systems With External Excitations

2001 ◽  
Author(s):  
Shuqing Yuan ◽  
Lihua Xie
Keyword(s):  
Vibration Suppression ◽  
Control Method ◽  
Active Vibration Control ◽  
Optimization Criterion ◽  
Dynamic Responses ◽  
Active Vibration Suppression ◽  
Method Effects ◽  
Active Vibration ◽  
Actuator Placement ◽  
Modal Space

Abstract Actuator placement is important to active vibration suppression. It is complex as it concerns many effects. In this paper, a new actuator position optimization criterion is proposed in which the effect of external excitations is considered. The criterion is applied in conjunction with the Independent Modal Space Control method. Effects of different modes are weighted to form a cost function according to their contributions to system dynamic responses, which directly reflect the effects of the external excitations. An example is given to validate the criterion.

scholarly journals Active vibration control of a railway pantograph

1997 ◽  
Vol 211 (2) ◽  
pp. 117-130 ◽  
Author(s):  
T. X. Wu ◽  
M. J. Brennan
Keyword(s):  
Degrees Of Freedom ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Control Force ◽  
Optimal Control Strategy ◽  
Advantages And Disadvantages ◽  
Full State Feedback ◽  
Active Vibration ◽  
The Stability

Current collection for electrical trains can be improved by the use of an active pantograph. To design such a system the behaviour of both the active pantograph and the overhead catenary system must be considered together. In this paper a two degrees-of-freedom model of an active pantograph, combined with a time-varying spring representing the catenary's influence, is employed and its dynamic performance is studied. Based on this model, three types of control strategies for an active pantograph are proposed and investigated, and all these models consider the interaction of the pantograph with the overhead wire. Two possible positions for mounting an actuator on the pantograph are considered and compared. From these active pantograph models the magnitude of the control force required can be estimated, and the advantages and disadvantages are discussed. The optimal control strategy shows the best performance, but introduces measurement difficulties because it needs full-state feedback. Classical feedback control is the least difficult to implement, but a compromise between the stability and the performance should be reached.

A numerical and experimental implementation and integration of Steiglitz–McBride algorithm with the frequency domain IIR filtering technique for active vibration control

2016 ◽  
Vol 24 (6) ◽  
pp. 1086-1100
Author(s):  
Utku Boz ◽  
Ipek Basdogan
Keyword(s):  
Computational Complexity ◽  
Vibration Control ◽  
Frequency Domain ◽  
Impulse Response ◽  
Time Domain ◽  
Vibration Suppression ◽  
Active Vibration Control ◽  
Infinite Impulse Response ◽  
Iir Filter ◽  
Active Vibration

In adaptive control applications for noise and vibration, finite ımpulse response (FIR) or ınfinite ımpulse response (IIR) filter structures are used for online adaptation of the controller parameters. IIR filters offer the advantage of representing dynamics of the controller with smaller number of filter parameters than with FIR filters. However, the possibility of instability and convergence to suboptimal solutions are the main drawbacks of such controllers. An IIR filtering-based Steiglitz–McBride (SM) algorithm offers nearly-optimal solutions. However, real-time implementation of the SM algorithm has never been explored and application of the algorithm is limited to numerical studies for active vibration control. Furthermore, the prefiltering procedure of the SM increases the computational complexity of the algorithm in comparison to other IIR filtering-based algorithms. Based on the lack of studies about the SM in the literature, an SM time-domain algorithm for AVC was implemented both numerically and experimentally in this study. A methodology that integrates frequency domain IIR filtering techniques with the classic SM time-domain algorithm is proposed to decrease the computational complexity. Results of the proposed approach are compared with the classical SM algorithm. Both SM and the proposed approach offer multimodal vibration suppression and it is possible to predict the performance of the controller via simulations. The proposed hybrid approach ensures similar vibration suppression performance compared to the classical SM and offers computational advantage as the number of control filter parameters increases.

scholarly journals Active Vibration Control of Launch Vehicle on Satellite Using Piezoelectric Stack Actuator

2018 ◽  
Author(s):  
Mehran Makhtoumi
Keyword(s):  
Vibration Control ◽  
Vibration Suppression ◽  
Virtual Work ◽  
Active Vibration Control ◽  
High Strength ◽  
Launch Vehicle ◽  
Design Parameters ◽  
Control Analysis ◽  
Active Vibration ◽  
Piezoelectric Stack Actuator

Satellites are subject to various severe vibration during different phases of flight. The concept of satellite smart adapter is proposed in this study to achieve active vibration control of launch vehicle on satellite. The satellite smart adapter has 18 active struts in which the middle section of each strut is made of piezoelectric stack actuator. Comprehensive conceptual design of the satellite smart adapter is presented to indicate the design parameters, requirements and philosophy applied which are based on the reliability and durability criterions to ensure successful functionality of the proposed system. The coupled electromechanical virtual work equation for the piezoelectric stack actuator in each active strut is drived by applying D'Alembert's principle. Modal analysis is performed to characterize the inherent properties of the smart adapter and extraction of a mathematical model of the system. Active vibration control analysis was conducted using fuzzy logic control with triangular membership functions and acceleration feedback. The control results conclude that the proposed satellite smart adapter configuration which benefits from piezoelectric stack actuator as elements of its 18 active struts has high strength and shows excellent robustness and effectiveness in vibration suppression of launch vehicle on satellite.

Tunable and Transferrable Bar Feeder Damping Design for Advanced Manufacturing

2013 ◽  
Author(s):  
Harry A. Pierson ◽  
Kumer V. Singh
Keyword(s):  
Vibration Suppression ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Viscoelastic Model ◽  
Advanced Manufacturing ◽  
Euler Beam ◽  
Batch Sizes ◽  
Active Vibration ◽  
Cnc Turning Centers ◽  
High Degree

The economical production of high-value, low-volume, machined components is an important subtopic of advanced manufacturing. Bar feeders, a well-established technology for adding a high degree of automation to CNC turning centers by feeding 12′ lengths of stock through the machine spindle, have limitations in this realm. They rely on supporting the entire length of the stock in a continuous fluid bearing in order to suppress potential vibrations. Although this results in excellent vibration suppression, long tooling changeovers make them impractical for small batch sizes. Additionally, the expense of the tooling can render them cost-prohibitive. Thus a bar feeder technology is desired that provides comparable vibration suppression for a wide variety of stock sizes without the need for size-specific tooling changes. In this, a movable point support having tunable viscoelastic properties is studied for controlling the vibration of varying lengths of bar stock in a given speed range. The transverse vibration of mounted bar stock is modeled as a Bernoulli-Euler beam. The effects of the support position, viscoelastic model, and their associated parameters on the resonant frequencies, damping ratios, and vibration response of the bar stock are studied. Such a study will be instrumental in developing passive/active vibration control strategies for future bar feeders.

Active vibration control based on modal controller considering structure-actuator interaction

2018 ◽  
Vol 32 (8) ◽  
pp. 3515-3521 ◽  
Author(s):  
Jinjun Jiang ◽  
Weijin Gao ◽  
Liang Wang ◽  
Zhaohua Teng ◽  
Yongguang Liu
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Active Vibration ◽  
Modal Controller

Effects of Actuators and Sensors Position on Independent Modal Control Performance

2012 ◽  
Author(s):  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Natural Frequencies ◽  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Point Of View ◽  
Control Technique ◽  
Modal Control ◽  
Sensors And Actuators ◽  
Active Vibration

Independent modal control technique allows to change the eigenvalues of a system, without changing its eigenvectors. From a mechanical point of view, it means it is possible to modify the natural frequencies and the damping of a n-DoF system, letting modal shapes unchanged. Independent modal control can be profitably used in active vibration control increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. This work demonstrates how the performance of the control depends on the number and position of sensors and actuators used besides, obviously, on the reduced model used to synthesize the control itself. Finally the paper suggests a simple optimum function to minimize the spillover effects due to unmodeled modes. Theoretical aspects are supported by numerical simulations.

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