Search results for "Vibration control"

A mixed H<inf>2</inf>/H<inf>∞</inf>-based semiactive control for vibration mitigation in flexible structures

2009

In this paper, we address this problem through the design of a semiactive controller based on the mixed H 2 /H ∞ control theory. The vibrations caused by the seismic motions are mitigated by a semiactive damper installed in the bottom of the structure. It is meant by semiactive damper, a device that absorbs but cannot inject energy into the system. Sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities (LMIs). A controller that guarantees asymptotic stability and a mixed H 2 /H ∞ performance is then developed. An algorithm is proposed to handle the semiactive nature of the actuator. The performance of the controller is experimentally evalu…

Vibration Control of a Base-Isolated Building using Wavelets

2011

Author's version of a chapter in the book: Proceedings of the 18th IFAC World Congress 2011. Also available from the publisher at: http://dx.doi.org/10.3182/20110828-6-IT-1002.03169

Computer active control of damping fluid of a racing superbike suspension scheme for road safety improvement spin-off

2008

This paper describes in detail a computational investigation of a newly-conceived scheme of hydraulic active racing motorcycle suspension and its design application based on a computer-aided control of damping fluid. Through ad hoc tests on a full-scale model setup and the theoretical approach of a non linear 8th-order suspension scheme, this study gives enhancement of the damping fluid active control on the feedback branch of the entire control system for significant improvement of the suspension response to typical road inputs. Briefly, the fluid flow in suspension dampers - generated through well-suited high-pressure hydraulic circuit - shall be conveniently controlled in direction and m…

A Semiactive Vibration Control Design for Suspension Systems with Mr Dampers

2011

Published version of a chapter published in the book: Vibration Analysis and Control - New Trends and Developments. Also available from the publisher at: http://www.intechopen.com/source/pdfs/17688/InTech-A_semiactive_vibration_control_design_for_suspension_systems_with_mr_dampers.pdf. OA

Semiactive vibration control of nonlinear structures through adaptive backstepping techniques withH∞performance

2011

This article presents a new approach to the vibration mitigation problem in structures subject to seismic motions. These kinds of structures are characterised by the uncertainties of the parameters that describe their dynamics, such as stiffness and damping coefficients. Moreover, the dampers used to mitigate the vibrations caused by earthquakes are usually nonlinear devices with frictional or hysteretic dynamics. We propose an adaptive backstepping controller to account for the uncertainties and the nonlinearities. The controller is formulated in such a way that it satisfies an H∞ performance. It is designed for a 10-storey building whose base is isolated with a frictional damper (passive …

The TLCD Passive Control: Numerical Investigations vs. Experimental Results

2012

Very recently the tuned liquid column damper (TLCD) is receiving an increasing interest from researchers concerned with vibration control, to be considered an alternative device with respect to the tuned mass damper (TMD), since the former has low cost, easy adjustment, flexible installation. However, in recent studies the authors [1] have pointed out that for TMD the analytical formulation provides results that are in good agreement with the experimental ones, while for TLCD it has been deducted that the analytical formulation needs further investigation. In fact using the classical formulation of the problem, numerical results are very different from the experimental results obtained by t…

Vibration mitigation of the Silver Madonna during the procession in Palermo: preliminary study

2010

Vibration control of base-isolated structures using mixed H2/H∞ output-feedback control

2009

A mixed H2/ H∞ output-feedback control design methodology for vibration reduction of base-isolated building structures modelled in the form of second-order linear systems is presented. Sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities. A controller that guarantees asymptotic stability and a mixed H2/ H∞ performance for the closed-loop system of the structure is developed, based on a Lyapunov function. The performance of the controller is evaluated by means of simulations in MATLAB/Simulink.

An LMI approach to vibration control of base-isolated building structures with delayed measurements

2010

In this article, we address a convex optimisation approach to the problem of state-feedback H∞ control design for vibration reduction of base-isolated building structures with delayed measurements, where the delays are time-varying and bounded. An appropriate Lyapunov-Krasovskii functional and some free-weighting matrices are utilised to establish some delay-range-dependent sufficient conditions for the design of desired controllers in terms of linear matrix inequalities. The controller, which guarantees asymptotic stability and an H∞ performance, simultaneously, for the closed-loop system of the structure, is then developed. The performance of the controller is evaluated by means of simula…

A Novel Mathematical Model For TLCD: Theoretical And Experimental Investigations

2014

In this paper, a novel mathematical model for the Tuned Liquid Column Damper (TLCD) is presented. Taking advantages of fractional derivatives and related concepts, a new equation of motion of the liquid inside the TLCD is obtained. Experimental laboratory tests have been performed in order to validate the proposed linear fractional formulation. Comparison among experimental results, numerical obtained using the classical formulation and numerical with the new linear fractional formulation are reported. Results in frequency domain show how the new linear fractional formulation can predict the real behavior of such a passive vibration control system, more correctly than the classical mathemat…