Wyniki wyszukiwania - Biblioteka Nauki

1

SDRE applied to position and vibration control of a robot manipulator with a flexible link

100%

Lima J. J. , Tusset A. M. , Janzen F. C. , Piccirillo V. , Nascimento C. B. , Balthazar J. M. , Brasil R. M. L. R. F.

Journal of Theoretical and Applied Mechanics

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2016

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tom Vol. 54 nr 4

1067--1078

EN

This paper presents position and vibration control of a flexible robot composed of two rigid and one flexible links. Position is controlled by the current applied to the DC motor armature. To control vibrations of the flexible structure, Shape Memory Alloys (SMA) are used. Due to phase transformations, the SMA can change its stiffness through temperature variation, considering and taking advantage of this characteristic the vibration control is done. Control is achieved via the State Dependent Ricatti Equations (SDRE) technique, which uses suboptimal control and system local stability search. The simulation results show the feasibility of the proposed control for the considered system.

2

Active vibration control with multi-objective control output for typical engineering equipment

100%

Jian X. , Tong-Yi Z. , Wei H. , Ming-Yi H.

Engineering Transactions

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2017

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tom Vol. 65, iss. 3

405--422

EN

In traditional active vibration control, a single-objective control output is often considered and constrained, but in fact some conflicting performance indexes are always emerging simultaneously and a one-sided method for pursuing only one excellent output is adopted, which may sacrifice other control characteristics. In this paper, a novel active vibration control with multi-objective control output was proposed for machinery equipment and sensitive equipment, and the latest artificial intelligence – multi-objective particle swarm optimization (MOPSO) was utilized, and the active controller was evaluated by the H∞ criterion, meanwhile an active control with a single-objective control output was also carried out for comparison. Numerical studies demonstrated that a pair of conflicting indexes could be balanced well in the proposed strategy, and thus only one blindly pursued control output was effectively overcome.

3

Active control of circular plate vibration by using piezoceramic actuators

100%

Leniowska L. , Leniowski R.

Archives of Control Sciences

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2003

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tom Vol. 13, no. 4

445-457

EN

An active vibration control system is proposed for suppressing small amplitude harmonic vibrations of a thin circular plate. This system integrates control algorithms, intelligent materials hardware and software technologies. The mathematical model of the physical system is based upon the geometry and properties of an experimantal set-up consisting of a hard-walled cylinder with a thin aluminium plate at the end. Primary excitation is provided by a low frequency loudspeaker installed centrally at the bottom of the cylinder. The vibrations of the plate are measured by the application of strain sensors. Intelligent materials such as 2-layer piezo disk elements (PZT) are used as the actuator. For the considered system, the OE (Output Error) method of discrete-time model identyfication for real-time active vibration control has been applied. On the basis of this model, the control algorithm based on pole-placement method has been developed. The obtained results show that the designed structure of a closed-loop system provides substantial vibration suppression.

4

Adaptive Active Control of Noise and Vibration

100%

Tokhi M. O.

Archives of Control Sciences

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2003

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tom Vol. 13, no. 2

117-139

EN

This paper presents the development of a unified approach to active control of noise and vibration.The design of an active control system in initially considered on the basis of a singleinput single-output(SISO) structure.The design procedure is formulated so as to allow on-line adaptation and control,and accordingly an adaptive control algorithm is devised.The design is the extended to the case of a single-input multi-output(SIMO)control structure. The control strategies thus devised are verirfied in the cancellation of broadband noise in a free-field medium, and in vibratio suppression in a cantilever beam in fixed-free and fixed-fixed modes.A comparative assessment of the results with SISO and SIMO control structures is presented and discussed.

5

Applications of platform mechanisms with 6 DOF in active vibration control systems.

100%

Tora G.

Archive of Mechanical Engineering

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2002

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tom Vol. XLIX, nr 2

179-192

EN

The paper introduces a new design of the platform mechanism with 6 DOF. The platform is supported on three active legs, each equipped with two rotating drives. The mechanism can be used in active vibration control systems. The values of drive angular velocities are precisely controlled, so that the transmission of the base vibration onto the platform could be minimal. The values of drive torques to be generated are determined. The mechanism was modelled using the Working Model(R) 3D. The effects of active vibration control are also presented.

PL

Artykuł zawiera propozycję nowej struktury mechanizmu platformowego o 6 stopniach swobody. Platforma tego mechanizmu jest podparta na ruchomej ramie trzema aktywnymi podporami, każda zawierająca po dwa napędy obrotowe. Mechanizm ten zastosowano do układu aktywnej redukcji drgań. Wykorzystując współrzędne wersorów związanych z ogniwami mechanizmu sformułowano układ osiemnastu równań algebraicznych położenia mechanizmu. Wprowadzono macierz jakobianową przekształcenia prędkości ramy w prędkości obrotowe napędów oraz macierz przekształcającą obciążenia przyłożone do platformy w momenty napędów. Wyznaczono wartości prędkości kątowych oraz momentów, które powinny być realizowane przez napędy, aby zminimalizować przenoszenie drgań podstawy na platformę. Wykonano model mechanizmu w programie Working Model 3D. Do wywołania drgań ramy zastosowano mechanizm platformowy Stewarta, w którym liniowe prędkości siłowników zmieniają się harmonicznie. Przedstawiono wyniki pracy układu aktywnej redukcji drgań w postaci wykresów przyspieszeń ramy i platformy oraz przedstawiono przebieg momentów napędów.

6

Active vibration control of a gyroscopic rotor using experimental modal analysis

100%

Jungblut J. , Fischer C. , Rinderknecht S. , Jungblut J. , Fischer C. , Rinderknecht S.

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7

Investigation of local and modal based active vibration control strategies on the example of an elastic system

100%

Peukert C. , Pöhlmann P. , Merx M. , Müller J. , Ihlenfeldt S.

Journal of Machine Engineering

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2019

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tom Vol. 19, No. 2

32--45

EN

Nowadays, feed axes are often equipped with multiple parallel-acting actuators in order to increase the dynamics of the machine tool. Also, additional actuators for active damping are widely used. Normally, the drives or actuators are controlled independently without consideration for the impact on each other. In contrast, by using the modal space control, the system can be decoupled and the modal control loops can be adjusted independently. This control approach is particularly suitable for motion systems, such as machine tools, which have more drives or actuators than degrees of freedom of movement. This paper deals with the pre-investigation of the modal-based vibration control for machine tools with additional actuators. The object of investigation is an elastic system with a movable saddle. The modal-based control is compared with a local control approach. The results obtained experimentally on the test rig are presented. The modal control is superior since, with the modal approach, each control loop corresponds to a specific vibration mode, and the control law for this loop is designed to provide the desired performance of the control system at the corresponding resonance frequency. The parameterisation of the control loops is simplified by modal control, since the modes can be controlled independently.

8

Simulations of the active cab suspension

100%

Tora G.

Journal of KONES

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2012

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tom Vol. 19, No. 1

455-464

EN

In the context of growing ergonomic concerns and pressing competition on the market, designing machines and vehicles offering a better operator comfort has become a major trend in development of heavy-duty machines and vehicles. During the ride over the rough terrain, the cab is subjected to excitations in the form of low frequency and high-amplitude vibration. This study investigates the vibration reduction strategy whereby the machine structure should incorporate an active suspension of the cab. An actuating mechanism is incorporated, connected to the machine frame and the cab, and placed in between. The main system component is a mobile platform to which the cab is attached. Respective drives set in motion the passive links in the actuating mechanism. The drives are equipped with cylinders capturing the instantaneous velocities derived in the control sub-system. The machine frame, subjected to kinematic excitations, performs a movement in space, which has to be measured with a set of sensors to support the control process. Basing on the measured movements of the machine frame, the control sub-system calculates the realtime values of the anticipated load and the required drive velocities. This study focuses on the development of a mechanical model of the actuating mechanism operating in several degree of freedom options. Solving the direct and inverse problems involving the position and velocity of the mechanism allows the Jacobean matrix to be applied in Newton-Euler’s equations. The purpose of the active suspension system is to stabilise the cab in the vertical position and to reduce its lateral vibrations and seat vibrations in the vertical. This study summarises the results of simulations performed to evaluate the system's performance and its power demand.

9

Development of Active Vibration Control System for Circular Plate by Using the 2-Layer Piezo Disk Elements

100%

Leniowska L. , Leniowski R.

Mechanika / Akademia Górniczo-Hutnicza im. St. Staszica

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2003

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tom T. 22, z. 3

337-346

EN

An active vibration control system is proposed for suppressing small amplitude harmonic vibrations of a thin circular plate. This system integrates control algorithms, intelligent materials, hardware and software technologies. The mathematical model of the physical system is based upon the geometry and properties of an experimental set-up consisting of a hard-walled cylinder with a thin aluminium plate at one end. Primary excitation is provided by a Iow frequency loudspeaker installed centrally at the bottom of the cylinder. The vibrations of the plate are measured by the application of strain sensors. Intelligent materials such as 2-layer piezo disk elements (PZT) are used as the actuator. For the considered system, the OE (Output Error) method of discrete-time model identification for real-time active vibration control has been applied. On the basis of this model, the control algorithm based on pole-placement method has been developed. The simulation results show that the designed structure of a close-loop system provifeedback contrdes substantial vibration suppression.

10

Temperature variation effect on the active vibration control of smart composite beam

88%

Salah M. , Boukhoulda F. B. , Nouari M. , Bendine K.

Acta Mechanica et Automatica

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2020

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tom Vol. 14, no. 3

166--174

EN

Due to their impressive capacity of sensing and actuating, piezoelectric materials have been widely merged in different industrial fields, especially aeronautic and aerospace area. However, in the aeronautic industry, the structures are operating under critical environ-mental loads such as high and very low temperature, which made the investigation of the effect of thermal forces on the piezoelectric struc-tures indispensable to reach the high functionality and performance. The present paper focuses on the effect of thermal loads on the active vibration control (AVC) of structures like beams. For this purpose, a finite element model of composite beam with fully covered piezoelec-tric sensor and actuator based on the well-known high order shear deformation theory is proposed by taking into account the electrical po-tential field and a linear temperature field. Hamilton’s principle is used to formulate the electro-thermo-mechanical governing equations. The negative velocity feedback controller is implemented to provide the necessary gain for the actuator. Different analyses are effectuated to present the effect of the temperature ranging from -70°C to 70°C on the active vibration control of the composite beam.

11

Hybrid control system for an AVC unit

88%

Stein G. J.

Archives of Control Sciences

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2003

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tom Vol. 13, no. 2

157-175

EN

The contribution summarieses research on an active vibration control system for heavy loads. The system is modeled as a single DOF oscillatory system with residual damping and a parallel force generator. As the force generator a stsndard air spring is used, whose internal pressure is proportionally controlled either by a flow control valve or a pressure control valve. Either proportional electro-pneumatic transducer is governed by a control voltage generated by an analogue controller based on a hybrid combination of feed-back and feed-forward control circuits. Experimental results on actuator sub-system identification and whole system frequency response funcitions of both modifications are presented. By proper setting of the gains favorite course of FRF coud be optained with no resonanse amplification, as assumed by simulation research.

12

Active Vibration Control of a Circular Plate with Clamped Boundary Condidtion

88%

Leniowska L. , Leniowski R.

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2001

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tom Vol. 22

145-156

EN

The paper presents a system identification and simulation of active vibration control for a clamped circular plate as well as its expermental implementation. The model is based upon the geometry and properties of an experimental set-up consisting of a hard-walled cylinder ith a thin plate at one end. The primary excitation is provided by a low frequency loudpeaker installed centraly at the bottom of the cylinder. Vibrations of the plate are measured by the application of several pairs of strain sensors located along the plate radius. The derived control action is applied to the plate by one shaker attached pointwise in its middle (SIMO system). In particular, obtained numerical values and structure of dynamical model are used to develop the P-PID control algorithm for vibration cancellation. Finally, the laboratory results obtained for the considered plate are presented.

13

Kontrola drgań konstrukcji

75%

Gołębiowska I. , Sakiewicz W.

Inżynieria i Aparatura Chemiczna

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2008

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tom Nr 4

30-31

PL

Kontrola drgań jest ważnym problemem, ze względu na wymagania konstrukcyjne i komfort użytkowników budowli. W artykule przedstawiono zwięzły opis nowoczesnych metod kontroli drgań konstrukcji z ich zaletami i ograniczeniami. Ponadto opisano też zasady działania kilku wybranych urządzeń kontroli drgań, z uwzględnieniem ich zastosowania.

EN

Vibration control is an important aspect in terms of structural reąuirements and comfort for people using a building. Modern methods of vibration control of structures with their advantages and limitations arę described in the paper. An operation of selec-ted control devices in the context of its application is also presented.

14

Intelligent methods for active noise and vibration control

75%

Tokhi M. O.

Archives of Acoustics

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2004

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tom Vol. 29, no. 2

259-273

EN

This paper presents an overview of intelligent soft computing techniques within the framework of active control of noise and vibration. Tools considered include genetic algorithms (GAs), neural networks (NNs) and fuzzy logic (FL). The paper highlights associated merits and potential benefits of the approaches in modelling and control of dynamic systems. These are demonstrated in the control of noise in free-field propagation and vibration suppression in 1D and 2D flexible structures. The paper shows that the potential benefits of the individual components can be exploited and approaches for design and development of hybrid soft-computing algorithms devised for modelling and control of dynamic systems. It is demonstrated that significant benefits in terms of performance can be gained with such hybrid algorithms.

15

Vibration suppression of truncated conical shells embedded with magnetostrictive layers based on first order shear deformation theory

75%

Mohammadrezazadeh S. , Jafari A. A.

Journal of Theoretical and Applied Mechanics

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2019

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tom Vol. 57 nr 4

957--972

EN

Vibration phenomena in mechanical structures including conical shells are usually undesirable. In order to overcome this problem, this study investigates active vibration control of isotropic truncated conical shells containing magnetostrictive actuators. The first-order shear deformation theory and the Hamilton principle are handled to obtain vibration equations. Moreover, a negative velocity feedback control law is used to actively suppress the vibration. The Ritz and modified Galerkin methods are utilized to obtain results of shell vibration. The results are validated by comparison with the results of literature and finite element software. Finally, the effects of control gain value, magnetostrictive layers thickness, isotropic layer thickness, length and semi-vertex angle of the conical shell on vibration suppression characteristics are obtained in details.

16

Active vibration control using piezoelectric sensor and actuator

75%

Giergiel M. , Sapińska-Wcisło A.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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2006

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tom z. 31

43-46

EN

In this paper application of piezomaterials used as distributed sensor and actuator for active vibration control is shown. The research proved that piezoelectric patches could be applied to systems in which the control of dynamic features is reąuired.

17

Comparison of Control Strategies for Active Vibration Control of Flexible Structures

75%

Ehmann C. , Nordmann R.

Archives of Control Sciences

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2003

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tom Vol. 13, no. 3

303-312

EN

In recent years several strategies for active vibration control of weakly damped flexible structures have been presented. Depending on the type and location fo actuator and sensor different control strategies lead to different performance and robustness behaviour oh the closed loop. The aim of the paper is to present convenient actuator-sensor-controller combinations and to compare their closed loop performance. A test rig representing a gantry milling machine allows ti validate practical applicability.

18

Application of Prediction Methods for Plate Vibration Suppression

75%

Leniowska L. , Leniowski R.

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2004

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tom Vol. 25

159-175

EN

In this paper, predictive feedback control is used to suppress circular plate vibrations. It is assumed that the system to be regulated is unknown. The plate is excited by a uniform force over the bottom surface generated by a loudspeaker. The axially-symmetrical vibrations of the plate are measured by the application of the strain sensors located along the plate radius and two centrally placed piezoceramic discs are used to cancel the plate vibrations. The control schemes presented in this work have the ability to predict the error sensor signals, to compute the control effort and to apply it to the actuator within one sampling period. For precise estimation of system behaviour the modified Runge-Kutta-3/8 neural network algorithm has been applied and tested. This control scheme is then illustrated through some numerical examples with simulations modeling the fuzzy predictive P-PI-PD controller and the improvement gained by incorporating a feed-forward path into the controller is demonstrated.

19

Active Vibration Control of the Circular Plate with Simply-Supported Boundary Condition

75%

Leniowska L.

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2003

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tom Vol. 24

109-124

EN

This paper presents the problem of the active vibration control of a simply-supported circular plate. The plate is excited by an uniform force over the bottom surface generated by a lodspeaker. The axially-symmtrical vibrations of the plate are measured by the application of the four accelometers located along the plate radius. The mathematical model of the plate was obtained by using analytical methods, as well as, on a base of regisrtation of a system response on a fixed excitation (a parametric system identification procedure has been employed). Firstly, a modal model for the vibration of the considered structure is presented and the state realisation of the model is given. Secondly. the OE (Output Error) identification method is used to derive the reduced linear model in the form of a transfer function of the second order. The obtained model is used to develop the linear feedback control algorithm for the cancellation of vibration by using the point force provided by a shaker (SIMO system). Finally, the laboratory results obtained for the considered plate are presented. The results show that in the chosen low-frequency limit the designed structure of a closed-loop system provides a substantial vibration suppression.

20

Feedforward Control of a Light-Weight Device Casing for Active Noise Reduction

75%

Wrona S. , Pawelczyk M.

Archives of Acoustics

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2016

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tom Vol. 41, No. 3

499--505

EN

It is possible to enhance acoustic isolation of the device from the environment by appropriately controlling vibration of a device casing. Sound insulation efficiency of this technique for a rigid casing was confirmed by the authors in previous publications. In this paper, a light-weight casing is investigated, where vibrational couplings between walls are much greater due to lack of a rigid frame. A laboratory setup is described in details. The influence of the cross-paths on successful global noise reduction is considered. Multiple vibration actuators are installed on each of the casing walls. An adaptive control strategy based on the Least Mean Square (LMS) algorithm is used to update control filter parameters. Obtained results are reported, discussed, and conclusions for future research are drawn.