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 A Review of Low-Frequency Active Vibration Control of Seat suspension Systems

2019 ◽  
Vol 9 (16) ◽  
pp. 3326 ◽  
Author(s):  
Zhao ◽  
Wang
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Low Frequency ◽  
Control Algorithms ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Low Frequency Vibration ◽  
Recent Developments ◽  
Active Vibration ◽  
Artificial Neural Network Ann

As a major device for reducing vibration and protecting passengers, the low-frequency vibration control performance of commercial vehicle seating systems has become an attractive research topic in recent years. This article reviews the recent developments in active seat suspensions for vehicles. The features of active seat suspension actuators and the related control algorithms are described and discussed in detail. In addition, the vibration control and reduction performance of active seat suspension systems are also reviewed. The article also discusses the prospects of the application of machine learning, including artificial neural network (ANN) control algorithms, in the development of active seat suspension systems for vibration control.

scholarly journals Experimental investigation of a single-degree-of-freedom system with Coulomb friction

2020 ◽  
Vol 99 (3) ◽  
pp. 1781-1799
Author(s):  
Luca Marino ◽  
Alice Cicirello
Keyword(s):  
Experimental Investigation ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Systematic Observation ◽  
Stick Slip ◽  
Friction Forces ◽  
Single Degree Of Freedom ◽  
Sdof System ◽  
Single Degree ◽  
Set Up

AbstractThis paper presents an experimental investigation of the dynamic behaviour of a single-degree-of-freedom (SDoF) system with a metal-to-metal contact under harmonic base or joined base-wall excitation. The experimental results are compared with those yielded by mathematical models based on a SDoF system with Coulomb damping. While previous experiments on friction-damped systems focused on the characterisation of the friction force, the proposed approach investigates the steady response of a SDoF system when different exciting frequencies and friction forces are applied. The experimental set-up consists of a single-storey building, where harmonic excitation is imposed on a base plate and a friction contact is achieved between a steel top plate and a brass disc. The experimental results are expressed in terms of displacement transmissibility, phase angle and top plate motion in the time and frequency domains. Both continuous and stick-slip motions are investigated. The main results achieved in this paper are: (1) the development of an experimental set-up capable of reproducing friction damping effects on a harmonically excited SDoF system; (2) the validation of the analytical model introduced by Marino et al. (Nonlinear Dyn, 2019. https://doi.org/10.1007/s11071-019-04983-x) and, particularly, the inversion of the transmissibility curves in the joined base-wall motion case; (3) the systematic observation of stick-slip phenomena and their validation with numerical results.

scholarly journals Active vibration isolation of high precision machines

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
C. Collette ◽  
S. Janssens ◽  
K. Artoos ◽  
C. Hauviller
Keyword(s):  
Active Control ◽  
High Precision ◽  
Vibration Isolation ◽  
Control Strategies ◽  
External Disturbances ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Atomic Force ◽  
Active Vibration ◽  
Precision Machines

This paper provides a review of active control strategies used to isolate high-precisionmachines (e.g. telescopes, particle colliders, interferometers, lithography machines or atomic force microscopes) from external disturbances. The objective of this review is to provide tools to develop the best strategy for a given application. Firstly, the main strategies are presented and compared, using single degree of freedom models. Secondly, the case of huge structures constituted of a large number of elements, like particle colliders or segmented telescopes, is considered.

The Active Control of Forced Vibration Produced by Arbitrary Disturbances

1985 ◽  
Vol 107 (1) ◽  
pp. 33-37 ◽  
Author(s):  
J. S. Burdess ◽  
A. V. Metcalfe
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Forced Vibration ◽  
Disturbance Observer ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Impact Forces ◽  
Mass Spring

This paper considers the vibration control of a single degree of freedom mass-spring-damper system when subjected to an arbitrary, unmeasurable disturbance. The idea of a disturbance observer is introduced and it is shown how an estimate of the excitation can be derived and used to generate a control, which reduces the vibration. This control is shown to be robust with respect to the parameters describing the behavior of the system. Experimental results are presented which show the efficacy of the method when the system is excited by periodic, random, and impact forces. Comments are made on the application of the method.

Polishing Characteristics of a Low Frequency Vibration Assisted Polishing Method

2013 ◽  
Vol 797 ◽  
pp. 450-454 ◽  
Author(s):  
Wei Min Lin ◽  
Sze Keat Chee ◽  
Hirofumi Suzuki ◽  
Toshiro Higuchi
Keyword(s):  
Surface Roughness ◽  
Piezoelectric Actuator ◽  
Medical Devices ◽  
Material Removal ◽  
Low Frequency ◽  
Experimental Results ◽  
Two Dimensional ◽  
Digital Devices ◽  
Low Frequency Vibration

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, and medical devices such as μ-TAS and solar optics etc. are increasing. To enhance precision, the structured molds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two-dimensional low frequency vibration (LFV) polishing actuator using PZT is proposed and developed. The LFV consists of four mechanical amplitude magnified actuators, a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a center piece. In the polishing experiments, HIPM workpieces were polished with WA slurry by the rotation & revolution type polishing method (RRP). The surface roughness of the work pieces and material removal amount (polished amount) was also evaluated. From the experimental results, it was found that the application of low frequency vibration is useful for realizing higher precision in the polishing of micro structured molds.

Robust Control Design of a Single Degree-of-Freedom Magnetic Levitation System by Quantitative Feedback Theory

2012 ◽  
Author(s):  
Feng Tian ◽  
Mark Nagurka
Keyword(s):  
Robust Control ◽  
Magnetic Levitation ◽  
Design Method ◽  
Control Design ◽  
Open Loop ◽  
Quantitative Feedback Theory ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Maglev System ◽  
Robust Control Design

A magnetic levitation (maglev) system is inherently nonlinear and open-loop unstable because of the nature of magnetic force. Most controllers for maglev systems are designed based on a nominal linearized model. System variations and uncertainties are not accommodated. The controllers are generally designed to satisfy gain and phase margin specifications, which may not guarantee a bound on the sensitivity. To address these issues, this paper proposes a robust control design method based on Quantitative Feedback Theory (QFT) applied to a single degree-of-freedom (DOF) maglev system. The controller is designed to successfully meet the stability requirement, robustness specifications, and bounds on the sensitivity. Experiments verify that the controller maintains stable levitation even with 100% load variation. Experiments prove that it guarantees the transient response design requirements even with 100% load change and 39% model uncertainties. The QFT control design method discussed in this paper can be applied to other open-loop unstable systems as well as systems with large uncertainties and variations to improve system robustness.

Design and Stability Analysis of Delayed Resonator With Acceleration Feedback

2013 ◽  
Author(s):  
Tomáš Vyhlídal ◽  
Nejat Olgac ◽  
Vladimír Kučera
Keyword(s):  
Vibration Suppression ◽  
Dynamics Analysis ◽  
Stability Boundaries ◽  
Single Degree Of Freedom ◽  
Stability Margins ◽  
Single Degree ◽  
Active Vibration Suppression ◽  
Acceleration Feedback ◽  
Active Vibration ◽  
The Stability

This paper deals with the problem of active vibration suppression using the concept of delayed resonator with acceleration feedback. A complete dynamics analysis of the resonator and its coupling with a single degree of freedom mechanical system are performed. It is shown that due to presence of a delay in the derivative feedback, the dynamics of the resonator itself, as well as the dynamics of its coupling with the system are of neutral character. Subsequently, the spectral approach is used to obtain the stability boundaries in the space of the resonator parameters. Both, analytical and numerical methods are employed in the analysis. As the contributions, we display a methodology to determine the resonator parameters in order to guarantee desirable functioning of the resonator and to provide safe stability margins. An example is included to demonstrate these analytical results.

Calculation of the Response of an Impulsively Excited Oscillator in an Infinite Acoustic Fluid

1981 ◽  
Vol 48 (4) ◽  
pp. 749-752 ◽  
Author(s):  
A. V. Clark ◽  
A. M. Whitman
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Sound Radiation ◽  
Wave Number ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Principal Effect ◽  
Hydrodynamic Solution ◽  
Acoustic Fluid ◽  
Excited Oscillator

The response of an impulsively excited single-degree-of-freedom oscillator submerged in an infinite acoustic fluid is considered. The character of the response is determined by the quantity ka; k is the wave number associated with the in-vacuo natural frequency of the oscillator, and a is a characteristic structural dimension. For low-frequency oscillators (ka ≪ 1), the response consists of two parts. The first is the usual hydrodynamic solution in which the effect of the fluid on the structure is that of an added mass. The second is much smaller (of order ka) and is significant only in a “boundary layer” in time of order a/c, with c the fluid sonic velocity. For high-frequency oscillators (ka ≫ 1), the principal effect of the fluid is a decay of oscillator vibration due to sound radiation.

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