A Comparison of Quarter, Half and Full Car Models for Predicting Vibration Attenuation of an Occupant in a Vehicle

This paper investigates the vibration control of a two-link flexible manipulator carried by a translational stage. The first and the second links are each driven by a stage motor and a joint motor. By treating the joint motor as a virtual spring, the two-link manipulator can be regarded as an integral flexible arm driven by the stage motor. A noncollocated controller is devised based on feedback from the deflection of the virtual spring, which can be measured by a shaft encoder. Stability of the closed-loop system is analyzed by examining the spatial derivatives of the modal functions. By including a bandpass filter in the feedback loop, residual vibrations can be attenuated without exciting high-frequency vibrations. The control method is simple to implement; its effectiveness is confirmed by simulation and experimental results.

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Optimized Design of Vibration Controllers for Steady and Transient Excitation of Flexible Rotors

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/pime_proc_1995_209_139_02 ◽

1995 ◽

Vol 209 (3) ◽

pp. 155-168 ◽

Cited By ~ 16

Author(s):

P S Keogh ◽

C Mu ◽

C R Burrows

Keyword(s):

Measurement Error ◽

Controller Design ◽

Optimized Design ◽

Rotor Vibration ◽

Transient Vibration ◽

Flexible Rotors ◽

Vibration Attenuation ◽

Measured Displacement ◽

Control Forces ◽

Shaft Surface

Controller designs for the attenuation of rotor vibration are investigated. Disturbance inputs leading to vibration are classified and related to control forces and defined control states. Optimization based on the H∞ norm is then used to minimize the influence of forcing disturbances, modelling error and measurement error. The practicalities of applying the method to an experimental rotor-bearing system, with hardware constraints on controller order, are stated. The controller was implemented experimentally to conduct steady state and mass loss tests. Steady synchronous, non-synchronous and transient vibration attenuation was demonstrated. It was also shown that measurement error, caused by shaft surface roughness, can be incorporated into the controller design without the need to remove the roughness component from the measured displacement signals. If the roughness influence is not included in the design and the uncontrolled vibration is small, unnecessary control forces may result, causing an increase in vibration.

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Preliminary Investigations of Machine Frame Vibration Damping Using Eddy Current Principle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.821.288 ◽

2016 ◽

Vol 821 ◽

pp. 288-294 ◽

Cited By ~ 2

Author(s):

George Juraj Stein ◽

Peter Tobolka ◽

Rudolf Chmúrny

Keyword(s):

Mathematical Model ◽

Natural Frequency ◽

Eddy Current ◽

Asynchronous Motor ◽

Oscillatory System ◽

Vibration Damping ◽

Combined Effects ◽

Magnetic Forces ◽

Novel Approach ◽

Vibration Attenuation

A novel approach to vibration attenuation, based on the eddy current principle, is described. The combined effects of all magnetic forces acting in the oscillatory system attenuate frame vibrations and, concurrently, decrease the damped natural frequency. A mathematical model of the forces balance in the oscillatory system was derived before. Some experimental results from a mock-up machine frame excited by an asynchronous motor are presented.

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Large low-frequency vibration attenuation induced by arrays of piezoelectric patches shunted with amplifier–resonator feedback circuits

Smart Materials and Structures ◽

10.1088/0964-1726/25/1/015004 ◽

2015 ◽

Vol 25 (1) ◽

pp. 015004 ◽

Cited By ~ 17

Author(s):

Gang Wang ◽

Shengbing Chen

Keyword(s):

Low Frequency ◽

Low Frequency Vibration ◽

Vibration Attenuation ◽

Feedback Circuits

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Vibration control using a beam-like adaptive tuned vibration absorber with an actuator-incorporated mass element

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes1301 ◽

2009 ◽

Vol 223 (7) ◽

pp. 1555-1567 ◽

Cited By ~ 10

Author(s):

P Bonello ◽

K H Groves

Keyword(s):

Vibration Control ◽

Effective Mass ◽

Tuning Range ◽

Excitation Frequency ◽

Vibration Absorber ◽

Time Varying ◽

Additional Advantage ◽

Expected Performance ◽

Vibration Attenuation ◽

Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) can retune itself in response to a time-varying excitation frequency, enabling effective vibration attenuation over a range of frequencies. For a wide tuning range the ATVA is best realized through the use of a beam-like structure whose mechanical properties can be adapted through servo-actuation. This is readily achieved either by repositioning the beam supports (‘moveable-supports ATVA’) or by repositioning attached masses (‘moveable-masses ATVA’), with the former design being more commonly used, despite its relative constructional complexity. No research to date has addressed the fact that the effective mass of such devices varies as they are retuned, thereby causing a variation in their attenuation capacity. This article derives both the tuned frequency and effective mass characteristics of such ATVAs through a unified non-dimensional modal-based analysis that enables the designer to quantify the expected performance for any given application. The analysis reveals that the moveable-masses concept offers significantly superior vibration attenuation. Motivated by this analysis, a novel ATVA with actuator-incorporated moveable masses is proposed, which has the additional advantage of constructional simplicity. Experimental results from a demonstrator correlate reasonably well with the theory, and vibration control tests with logic-based feedback control demonstrate the efficacy of the device.

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