Comparison of vibration control by confinement to conventional active vibration control methods

1997 ◽  
Author(s):  
William W. Clark ◽  
Fangning Sun ◽  
David J. Tarnowski
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Control Methods ◽  
Active Vibration

Active Control of Rotor Vibrations by Two Feedforward Control Algorithms

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Kari Tammi
Keyword(s):  
Vibration Control ◽  
Feedforward Control ◽  
Active Vibration Control ◽  
Fir Filter ◽  
Lms Algorithm ◽  
Control Methods ◽  
Rotor Vibration ◽  
Operating Range ◽  
Active Vibration ◽  
Adaptive Fir

Resonance vibrations (critical speeds) play a significant role in rotor vibration control. Active vibration control methods for rotors are studied to develop solutions to enhance machines’ dynamic behavior, durability, and operating range. This paper reports rotor vibration attenuation with a supplementary electromagnetic actuator located outside the rotor bearing span. Feedback and feedforward control system design are shown, and comparative experiments on two active vibration control methods for mass unbalance compensation are reported. The methods compared are adaptive FIR filter with the least mean squares (LMS) algorithm and convergent control (CC) method with a frequency-domain adaptation algorithm. The methods were experimentally validated on the rotor test rig (rotor weight 2.7 kg, length 560 mm, and first critical speed about 50 Hz). The feedback system provided wideband damping in the sub- and supercritical regions. The feedforward systems attenuated vibratory responses at the speed of rotation and its harmonic. The attenuation achieved was about 20 dB depending on the rotor speed. Also, discrete-time CC algorithm is shown to have a feedback equivalent circuit. The significance of feedback control lies in making the system phase-characteristics sufficiently smooth for feedforward control methods. Then, feedforward algorithms provided a good vibration damping performance over the operating range. CC was found to be a more effective and simpler algorithm for the purpose than the adaptive FIR filter with the LMS algorithm. The equivalent feedback circuit derived for CC, and systems similar to CC, facilitates their stability and robustness analysis.

scholarly journals Piezoelectric Pushers for Active Vibration Control of Rotating Machinery

1989 ◽  
Vol 111 (3) ◽  
pp. 298-305 ◽  
Author(s):  
A. B. Palazzolo ◽  
R. R. Lin ◽  
R. M. Alexander ◽  
A. F. Kascak ◽  
J. Montague
Keyword(s):  
Feedback Control ◽  
Vibration Control ◽  
Active Control ◽  
Active Vibration Control ◽  
Rotating Machinery ◽  
Nasa Lewis Research ◽  
Control Methods ◽  
Test Rig ◽  
Related Theory ◽  
Active Vibration

The active control of rotordynamic vibrations and stability by magnetic bearings and electromagnetic shakers has been discussed extensively in the literature. These devices, though effective, are usually large in volume and add significant weight to the stator. The use of piezoelectric pushers may provide similar degrees of effectiveness in light, compact packages. This paper contains analyses which extend quadratic regulator and derivative feedback control methods to the “prescribed displacement” character of piezoelectric pushers. The structrual stiffness of the pusher is also included in the theory. Tests are currently being conducted at NASA Lewis Research Center with piezoelectric pusher-based active vibration control. The paper presents results performed on the NASA test rig as preliminary verification of the related theory.

Active Vibration Control Methods of Axially Moving Materials - A Review

2004 ◽  
Vol 10 (4) ◽  
pp. 475-491 ◽  
Author(s):  
Jianjun Wang ◽  
Qihan Li
Keyword(s):  
Transfer Function ◽  
Vibration Control ◽  
Active Control ◽  
Control Method ◽  
Active Vibration Control ◽  
Control Methods ◽  
The Past ◽  
Active Vibration ◽  
Axially Moving ◽  
Active Wave

In this paper we provide a review of the state of the art for active vibration control of axially moving materials (string and beam, etc.) in the past ten years, with particular regard to the subjects of some important active control methods of axially moving strings. First, an introduction is given to explain the aims and scope of this paper. This is followed by a comprehensive discussion of the active wave control methods presented by many investigators in the past ten years, including feedback control methods (such as the modal control method, the direct velocity feedback control method and the control method via transfer function formulation), active wave control methods combining transfer function, boundary control methods using the Lyapunov function, the variable structure control method, the adaptive control method, the vibration control of an axially moving beam and the active control of a moving material with arbitrarily varying length, etc. Finally, we conclude with a discussion of several issues for future research in this area.

Sign in / Sign up

Export Citation Format

Share Document