Tesis sobre el tema "Actuator placement for vibration control"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Actuator placement for vibration control".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Potami, Raffaele. "Optimal sensor/actuator placement and switching schemes for control of flexible structures". Worcester, Mass. : Worcester Polytechnic Institute, 2008. http://www.wpi.edu/Pubs/ETD/Available/etd-042808-124333/.
Texto completoKeywords: hybrid system, PZT actuators, performance enchancement, actuator placement, actuator switching. Includes bibliographical references (leaves 102-108).
Anthony, David Keith. "Robust optimal design using passive and active methods of vibration control". Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312863.
Texto completoSwathanthira, Kumar Murali Murugavel Manjakkattuvalasu. "Implementation of an actuator placement, switching algorithm for active vibration control in flexible structures". Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-1120102-210634.
Texto completoKeywords: Actuator placement algorithm; piezoelectric actuators; LQR; Galerkin; supervisory control; active vibration control; FEA; switching policy; dSPACE. Includes bibliographical references (p. 58-64).
Suwit, Pulthasthan Information Technology & Electrical Engineering Australian Defence Force Academy UNSW. "Optimal placement of sensor and actuator for sound-structure interaction system". Awarded by:University of New South Wales - Australian Defence Force Academy. School of Information Technology and Electrical Engineering, 2006. http://handle.unsw.edu.au/1959.4/38741.
Texto completoSzczepanski, Robert Walter. "Optimal placement of actuators and sensors for vibration control using genetic algorithms". Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341754.
Texto completoLuleci, Ibrahim Furkan. "Active Vibration Control Of Beam And Plates By Using Piezoelectric Patch Actuators". Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615491/index.pdf.
Texto completopositive position feedback (PPF), resonant control (RC), integral resonant control (IRC) and positive position feedback with feed-through (PPFFT) are designed based on both reduced order finite element model and the system identification model. PPFFT, is a modified version of PPF which is proposed as a new controller in this study. Results of real- time control experiments show that PPFFT presents superior performance compared to its predecessor, PPF, and other two methods. In the second part of the study, it is focused on controlling the first three modes of a rectangular plate with four clamped edges. Best location alternatives for three piezoelectric actuators are determined with modal strain energy method. Based on the reduced order finite element model, three PPFFT controllers are designed for three collocated transfer functions. Disturbance rejection performances show the convenience of PPFFT in multi-input multi-output control systems. Performance of the control system is also verified by discrete-time simulations for a random disturbance representing the in-flight aircraft vibration characteristics.
Jha, Akhilesh K. "Vibration Analysis and Control of an Inflatable Toroidal Satellite Component Using Piezoelectric Actuators and Sensors". Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28243.
Texto completoPh. D.
Xue, Kai. "Modal filtering for active control of floor vibration under impact loading". Kyoto University, 2018. http://hdl.handle.net/2433/232024.
Texto completoMagee, Warwick R. "Development of an electromagnetic actuator for active vibration control". Thesis, Queensland University of Technology, 1997.
Buscar texto completoJia, Jianhu. "Optimization of piezoelectric actuator systems for vibration control of flexible structures". Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39754.
Texto completoPh. D.
Stander, Cornelius Johannes. "The passive control of machine tool vibration with a piezoelectric actuator". Diss., University of Pretoria, 2000. http://hdl.handle.net/2263/23038.
Texto completoDissertation (M Eng (Mechanical Engineering))--University of Pretoria, 2000.
Mechanical and Aeronautical Engineering
unrestricted
Ibrahim, Rashidi. "Vibration assisted machining : modelling, simulation, optimization, control and applications". Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/4732.
Texto completoMykhaylyshyn, Volodymyr. "Application of Active Magnetic Force Actuator for Control of Flexible Rotor System Vibrations". Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1322845232.
Texto completoAridogan, Mustafa Ugur. "Performance Evaluation Of Piezoelectric Sensor/actuator On Investigation Of Vibration Characteristics And Active Vibration Control Of A Smart Beam". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612005/index.pdf.
Texto completoRussillo, Carolynn M. "A study of actuator reconfiguration and related implementation issues in active vibration damping". Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/101257.
Texto completoM.S.
Goldstein, Andre L. "Control of Sound Transmission with Active-Passive Tiles". Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/27913.
Texto completoPh. D.
Beache, Kemrom Vidol Ariel. "Active vibration control of a smart beam under rotation". reponame:Repositório Institucional da UFABC, 2016.
Buscar texto completoDissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia Mecânica, 2016.
Uma viga em rotação é equipada com sensores e atuadores piezoelétricos em conjunto com um controlador proporcional-derivativo (PD) ou um controlador do tipo regulador linear quadrático (LQR) para comparação. O objetivo dos controladores é a minimização da deflexão na extremidade livre da estrutura devido ao seu movimento em torno do eixo de rotação. Utilizando o efeito piezoelétrico ¿ a geração de uma voltagem quando a estrutura está sujeita a uma tensão mecânica ¿ e, inversamente, a geração de uma deformação quando sujeito a uma voltagem, a estrutura do tipo viga é considerada como um sistema inteligente, tendo a capacidade de detectar e corrigir deflexões ao longo de seu comprimento. Usando as equações de Lagrange, a equação governante do movimento é obtida para a viga. A força (momento) e a rigidez da cerâmica piezoelétrica são subsequentemente adicionadas à equação governante da viga. A função de Heaviside é usada para a localização do atuador piezoelétrico ao longo da viga. A posição do atuador piezoelétrico varia a partir da extremidade engastada até a extremidade livre da viga ocupando três diferentes posições. O comprimento do atuador piezoelétrico é de um terço do comprimento da viga. O melhor posicionamento do piezoelétrico dentre os investigados é determinado para os três primeiros modos de vibração. Duas técnicas de controle linear são investigadas com o objetivo de eliminar a vibração na estrutura flexível: PD e LQR. O grau de liberdade associado ao movimento de rotação da viga (e suas derivadas) é prescrito por meio de um perfil pré-definido.
A rotating beam is fitted with piezoelectric sensors and actuators in conjunction with a proportional-derivative (PD) controller and a linear quadratic regulator (LQR) controller in order to minimize the deflection of the tip due to the rotational motion of the structure. Utilizing the piezo effects, the generation of a voltage, when subjected to a strain, and conversely the generation of a strain when subjected to a voltage, the system is considered as smart, having the ability to sense and correct deflections of the tip of the beam. Using the equations of Lagrange, the governing equation of motion is derived for the beam. The force (moment) and the stiffness of the piezo ceramic are subsequently added to the governing equation of the beam. In a model of the system, a Heaviside function is used to manipulate the position of the piezo. The position of the piezo will be varied from the root of the beam (the clamped end) to the free end of the beam, occupying three different positions; the length of the piezo is a third of the beam¿s length. The best position of the piezo is determined for three modes of vibration. Two linear control techniques are investigated in order to eliminate vibration in the flexible structure. The degree of freedom associated with the rotational motion is obtained by a predefined profile.
井上, 剛志, Tsuyoshi INOUE, 軍. 劉, Jun LIU, 祐亮 吉村, Yusuke YOSHIMURA, 幸男 石田 y Yukio ISHIDA. "外乱オブザーバを用いた非線形回転軸系の振動制御と不つりあい推定". 日本機械学会, 2005. http://hdl.handle.net/2237/8975.
Texto completoWilson, Thomas Lawler. "A multi-coil magnetostrictive actuator". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28243.
Texto completoCommittee Chair: Zinn, Ben T.; Committee Member: Book, Wayne; Committee Member: Glezer, Ari; Committee Member: Neumeier, Yedidia; Committee Member: Seitzman, Jerry.
Schäfer, Carsten [Verfasser]. "Optimization approaches for actuator and sensor placement and its application to model predictive control of dynamical systems / Carsten Schäfer". München : Verlag Dr. Hut, 2015. http://d-nb.info/1079768459/34.
Texto completoSheng, Lizeng. "Finite Element Analysis and Genetic Algorithm Optimization Design for the Actuator Placement on a Large Adaptive Structure". Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/30184.
Texto completoPh. D.
Fodor, Szabolcs. "Towards semi-automation of forestry cranes : automated trajectory planning and active vibration damping". Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-140256.
Texto completoJansson, Fredrik y Oskar Johansson. "A Study of Active Engine Mounts". Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2089.
Texto completoAchieving better NVH (noise, vibration, and harshness) comfort necessitates the use of active technologies when product targets are beyond the scope of traditional passive insulators, absorbers, and dampers. Therefore, a lot of effort is now being put in order to develop various active solutions for vibration control, where the development of actuators is one part.
Active hydraulic engine mounts have shown to be a promising actuator for vibration isolation with the benefits of the commonly used passive hydraulic engine mount in addition to the active ones. In this thesis, a benchmark of actuators for active vibration control has been carried out. Piezoelectric actuators and electromagnetic actuators are studied further and two methods to estimate parameters for electromagnetic actuators have been developed. A parameterized model of an active hydraulic engine mount valid for frequencies from zero to about 300 Hz, has also been developed. Good agreement with experimental data has been achieved.
Deng, Jie. "Rear Axle Gear Whine Noise Abatement via Active Vibration Control of the Rear Subframe". University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1447772359.
Texto completoHersh, Michael J. "Position control and vibration suppression of a flexible beam-like structure cantilevered from a rotary actuator within a gravitational field". Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/94466.
Texto completoM.S.
Norlander, Hans. "Modelling and Control Methods with Applications to Mechanical Waves". Doctoral thesis, Uppsala universitet, Avdelningen för systemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229793.
Texto completoJuston, John M. "Theoretical and experimental study into the dynamics and control of a flexible beam with a DC-servo motor actuator". Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/50029.
Texto completoMaster of Science
incomplete_metadata
Dunbabin, Matthew D. "The influence of temperature on PZT sensors & actuators for active vibration control of flexible structures". Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36162/7/36162_Digitised%20Thesis-4_Redacted.pdf.
Texto completoNguyen, Thanh Hung. "Conception et commande d’un système multi-actionneurs piézo-électriques pour l’assistance au forgeage par vibrations". Thesis, Paris, ENSAM, 2014. http://www.theses.fr/2014ENAM0007/document.
Texto completoThe superimposition of vibration during forging is known to reduce force and improve the mechanical properties of the workpiece. Until now, ultrasonic frequencies were used, but more recent results have shown that more complex vibrations at low frequencies had similar effects, with less power. Although piezoelectric actuator can generate high forces and have large rigidity, they are still limited with regards to the necessary forces during forging.Therefore, this work addresses the design of a worktool combining several actuators to generate complex vibration waveforms consisting in rotations in the plane of the die and displacement along the vertical direction. It relies on the use of flexible hinges due to the small displacement generated by the actuators. The design and control of the system is realized using a systemic approach based on the Energetic Macroscopic Representation. Thank to this tool, the control is systematically deduced by inversion. The design and its control strategy is validated experimentally on a mock-up specially realized during this work
Carvalhal, Ricardo [UNESP]. "Controle ativo de vibrações em estruturas espaciais tipo treliças usando controladores IMSC". Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/94550.
Texto completoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Este trabalho apresenta o desenvolvimento analítico da modelagem de estruturas flexíveis do tipo treliça com o objetivo de atenuação de vibrações através do uso de técnicas de controle ativo. Atuadores de pilha piezelétricos são usados para exercer as forças de controle na estrutura, os quais substituem barras inteiras ou somente uma parte delas. Estes tipos de atuadores, também, satisfazem a necessidade de obtenção de estruturas leves. O posicionamento ótimo desses atuadores e de sensores é encontrado através da norma Hx, que é usada como função objetivo. Como técnica de controle é aplicado o Controle no Espaço Modal Independente (IMSC), no qual os estados são estimados por um estimador modal e são realimentados de acordo com a teoria de controle ótimo, o Regulador Linear Quadrático (LQR). O IMSC é eficiente computacionalmente mesmo aplicado a sistemas de alta ordem e também reduz os efeitos de spillover. Uma melhoria do IMSC, o Controle Modal Eficiente (EMC) também é apresentado com o propósito de reduzir as amplitudes das forças de controle. O modelo matemático da estrutura inteligente é obtido a partir do Método dos Elementos Finitos (MEF) considerando o acoplamento eletromecânico entre os atuadores de pilhas piezelétricos e a estrutura base. O projeto de uma treliça espacial, o posicionamento ótimo dos atuadores e sensores e o controle ativo de vibração são apresentados em simulações numéricas. Os resultados mostram que ambos os controladores aumentam o amortecimento da estrutura e, ainda, o EMC reduz as amplitudes das forças de controle.
This work presents the analytic development of the modeling of flexible truss structures with the aim to suppress the mechanical vibration using active control techniques. Piezoelectric stack actuators are used to produce control force in the structure, which can replace an entire bar or can be coupled to structural members. They also satisfy the necessity to obtain lighter structures. The optimal placement of actuators and sensors is found through the Hã norm as objective function. As control technique is presented the Independent Modal Space Control (IMSC), in which a modal estimator is used and the Linear Quadratic Regulator (LQR) feedback the estimated states according the optimal control theory. IMSC is computationally efficient also applied in high order system and reduces the negative effects of the control and observer spillover. An improvement in the IMSC is the Efficient Modal Control (EMC) that is proposed to reduce the amplitudes of control forces. The mathematical model of the intelligent structure is obtained from Finite Elements Method (FEM) considering the electromechanical coupling between the piezoelectric stack actuators and the base structure. The design of a space truss structure, the optimal placement of active members and the active damping vibration control is numerically implemented. Two control techniques are tested and compared: IMSC and EMC. Results show that the controllers increase the damping of the structure noticeably. The EMC controller provides better performance, reducing the amplitudes of control forces.
Carvalhal, Ricardo. "Controle ativo de vibrações em estruturas espaciais tipo treliças usando controladores IMSC /". Ilha Solteira : [s.n.], 2005. http://hdl.handle.net/11449/94550.
Texto completoBanca: Luiz de Paula do Nascimento
Banca: Marcus Antonio Viana Duarte
Resumo: Este trabalho apresenta o desenvolvimento analítico da modelagem de estruturas flexíveis do tipo treliça com o objetivo de atenuação de vibrações através do uso de técnicas de controle ativo. Atuadores de pilha piezelétricos são usados para exercer as forças de controle na estrutura, os quais substituem barras inteiras ou somente uma parte delas. Estes tipos de atuadores, também, satisfazem a necessidade de obtenção de estruturas leves. O posicionamento ótimo desses atuadores e de sensores é encontrado através da norma Hx, que é usada como função objetivo. Como técnica de controle é aplicado o Controle no Espaço Modal Independente (IMSC), no qual os estados são estimados por um estimador modal e são realimentados de acordo com a teoria de controle ótimo, o Regulador Linear Quadrático (LQR). O IMSC é eficiente computacionalmente mesmo aplicado a sistemas de alta ordem e também reduz os efeitos de spillover. Uma melhoria do IMSC, o Controle Modal Eficiente (EMC) também é apresentado com o propósito de reduzir as amplitudes das forças de controle. O modelo matemático da estrutura inteligente é obtido a partir do Método dos Elementos Finitos (MEF) considerando o acoplamento eletromecânico entre os atuadores de pilhas piezelétricos e a estrutura base. O projeto de uma treliça espacial, o posicionamento ótimo dos atuadores e sensores e o controle ativo de vibração são apresentados em simulações numéricas. Os resultados mostram que ambos os controladores aumentam o amortecimento da estrutura e, ainda, o EMC reduz as amplitudes das forças de controle.
Abstract: This work presents the analytic development of the modeling of flexible truss structures with the aim to suppress the mechanical vibration using active control techniques. Piezoelectric stack actuators are used to produce control force in the structure, which can replace an entire bar or can be coupled to structural members. They also satisfy the necessity to obtain lighter structures. The optimal placement of actuators and sensors is found through the Hã norm as objective function. As control technique is presented the Independent Modal Space Control (IMSC), in which a modal estimator is used and the Linear Quadratic Regulator (LQR) feedback the estimated states according the optimal control theory. IMSC is computationally efficient also applied in high order system and reduces the negative effects of the control and observer spillover. An improvement in the IMSC is the Efficient Modal Control (EMC) that is proposed to reduce the amplitudes of control forces. The mathematical model of the intelligent structure is obtained from Finite Elements Method (FEM) considering the electromechanical coupling between the piezoelectric stack actuators and the base structure. The design of a space truss structure, the optimal placement of active members and the active damping vibration control is numerically implemented. Two control techniques are tested and compared: IMSC and EMC. Results show that the controllers increase the damping of the structure noticeably. The EMC controller provides better performance, reducing the amplitudes of control forces.
Mestre
Neto, Hélio Jacinto da Cruz. "Otimização do posicionamento de sensores e atuadores para o controle com realimentação de saída utilizando critério de desempenho quadrático". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-25052018-174813/.
Texto completoFlexible structures are subject to unknown excitations that may cause damage. One of the possible artifices to deal with this problem is the control theory of dynamical systems. In particular, a technique that raises the interest for application in this class of systems is the optimal control, due to its good properties of response and feasibility, as it can be applied even through analog circuits. A drawback of this technique is the need for a number of sensors equal to the number of states, which for structures is impracticable. As an alternative, the usual procedures of using only measured signals for feedback can be employed. However, these cases do not consider the design of the input and output matrices, a determining factor for vibration control in structures. The purpose of this paper is to fill this gap. Initially, some concepts of the theories of optimal control, structural dynamics and series discretization methods are introduced. Then, the optimality conditions are determined considering the gain and locations of sensors and actuators as the optimization variables. Given these conditions, we investigate the main challenges to solve these equations, given by the existence of parameters that stabilize the system and the dependence of the optimum point in relation to the initial condition of the system. The first one is solved from the specification of the linear system to a modal form and using Lyapunov control functions, which additionally provides the result that the collocated control is an optimal control. For the second two solutions are proposed, one being used to determine the positions of the actuators to design a LQR control with satisfactory performance, and the other to determine the gains and positions of the sensors in order to obtain an output feedback control with close performance to the designed LQR. The results obtained from the application of the methodology developed in structural dynamics examples revealed a remarkable performance. Even for a small ratio between the number of sensors by the number of states a performance equivalent to the LQR was obtained, also exhibiting considerable robustness properties in relation to the optimization variables. It is concluded that the developed methodology is a good alternative for LQR and LQG control techniques.
Perini, Efrain Araujo [UNESP]. "Redução de vibrações de rotores utilizando atuadores magnéticos e sistema de controle feedforward". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/94510.
Texto completoFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Este trabalho apresenta o desenvolvimento de uma análise teórica do desempenho de um sistema de controle ativo utilizando mancais magnéticos como atuadores de não-contato para a redução de vibrações em rotores. São analisados três modelos de rotores, sendo que em um deles aplica-se apenas o controle feedback e os outros são suportados apenas por mancais magnéticos, os quais também são os atuadores do controlador. Assim, Luna arquitetura de controle tipo feedforward é empregada sobreposta ao sistema de controle feedback dos atuadores nestes dois modelos, sendo urna análise realizada em relação ao desempenho do sistema de controle quanto às diferentes geometrias de distribuição de massa acopladas ao eixo do rotor. O enfoque principal deste trabalho é voltado para a análise do desempenho do sistema de controle em função da posição e quantidade dos sensores de erro (onde se deseja minimizar as vibrações) em relação à posição dos atuadores e das forças de excitação. As excitações são do tipo síncronas e sub-síncronas que normalmente aparecem em rotores com elevadas velocidades de rotação, como as turbomáquinas. Também é realizada urna análise das forças de controle necessárias a serem aplicadas pelos atuadores para se obter urna redução dos níveis de vibração do rotor na posição dos sensores de erro do sistema feedforward. A análise é executada empregando modelos de rotores desenvolvidos pelo método da matriz de impedância. Esta pesquisa também apresenta Luna aplicação da técnica de controle Feedforward em acústica, que realiza a depuração da voz para comunicação em ambientes ruidosos.
This research work brings a theoretical analysis of a control system performance that uses magnetic bearings as non-contact actuators to reduce rotor vibrations. It is analyzed three rotor models, in which one of them operates under the feedback control only. The other models are supported by magnetic bearings only, which also are the controller system actuators. Thus, a feedforward control scheme is applied over the feedback control inherent to the AMB control circuit. The analysis is carried out over these two last models regarding to the control performance for different geometry of mass distribution along the rotor. The focus of this work is to analyze the controller performance according to the sensor quantity and placement (where the vibrations are desired to be minimized) regarding to the actuator position and to the exciting forces. The subsynchronous and synchronous excitations are considered here since they frequently occur in high rotating speed rotors, as in the turbomachinery scenario. Also, the control force required by the actuators is monitored according to the sensors placement to reduce the local vibrations level and the analysis was carried out using the impedance matrix rotor modeling. Further, this work brings a modeling and an application of the feedforward active control scheme in the acoustics field used for voice extraction for communication in noisy environments.
Сторожук, С. Б. y І. В. Коц. "Навісний гідропривідний ударно-вібраційний молот для ущільнення жорстких бетонних сумішей". Thesis, ВНТУ, 2018. http://ir.lib.vntu.edu.ua//handle/123456789/20984.
Texto completoDesigned mounted shock vibration equipment with hydraulic drive hydroficated from the base of the machine. Tests have been carried out, which confirmed the suitability and practical expediency of this equipment for use in the construction industry. The recommendations for the design and technology of the use of this equipment in the production conditions are given.
Perini, Efrain Araujo. "Redução de vibrações de rotores utilizando atuadores magnéticos e sistema de controle feedforward /". Ilha Solteira : [s.n.], 2009. http://hdl.handle.net/11449/94510.
Texto completoAbstract: This research work brings a theoretical analysis of a control system performance that uses magnetic bearings as non-contact actuators to reduce rotor vibrations. It is analyzed three rotor models, in which one of them operates under the feedback control only. The other models are supported by magnetic bearings only, which also are the controller system actuators. Thus, a feedforward control scheme is applied over the feedback control inherent to the AMB control circuit. The analysis is carried out over these two last models regarding to the control performance for different geometry of mass distribution along the rotor. The focus of this work is to analyze the controller performance according to the sensor quantity and placement (where the vibrations are desired to be minimized) regarding to the actuator position and to the exciting forces. The subsynchronous and synchronous excitations are considered here since they frequently occur in high rotating speed rotors, as in the turbomachinery scenario. Also, the control force required by the actuators is monitored according to the sensors placement to reduce the local vibrations level and the analysis was carried out using the impedance matrix rotor modeling. Further, this work brings a modeling and an application of the feedforward active control scheme in the acoustics field used for voice extraction for communication in noisy environments.
Orientador: Luiz de Paula do Nascimento
Coorientador: Vicente Lopes Junior
Banca: Gilberto Pechoto de Melo
Banca: Kátia Luchese Cavalca Dedini
Mestre
Teixeira, Rafael Luís. "Projeto, construção e caracterização de um amortecedor ativo controlado por atuador piezoelétrico". Universidade Federal de Uberlândia, 2007. https://repositorio.ufu.br/handle/123456789/14796.
Texto completoThis thesis presents the design methodology, the construction of a prototype and the experimental validation of an active vibration damper witch is controlled by a piezoelectric actuator. The proposed device has two flexible metallic bellows connected to a rigid reservoir filled with a viscous fluid. When one of the bellows is connected to a vibrating structure a periodic flow passes through a variable internal orifice and the damping effect is produced. The size of the orifice is adjusted by a piezoelectric control system that positions the conical core into a conical cavity. The damper device finite element computational model was developed considering that the valve body is rigid and that the fluid - structure iteration occurs between the fluid and the flexible bellows. This model is discretized using a lagrangean-eulrian formulation. The actuator has a closed flexible metallic structure that amplifies the displacement produced by an internally mounted stack of piezoelectric ceramic layers, and it is also modeled by the finite element method. The damper prototype was built and experimental tests using impulsive and harmonic excitations were conducted to determine its dynamic behavior and also to validate the developed computational models. The simulation and experimental results are compared by curves that relate the damping coefficient with the size of the orifice. Reduced dynamical models are proposed to represent the behavior of the damper device with fixed and variable orifice sizes. A local classic PID controller for the piezoelectric actuator was design to assure that the valve core assume the correct position, providing the commanded damping coefficient. The damper device was applied to a vibration system that represents the model of a quarter-car vehicle. One on-off controller and another fuzzy controller were design to control the vibrations of the vehicle equipped with the proposed active damper. Experimental tests shown that the damping coefficient values, commanded by the global controller, were achieved in time intervals lesser than 10 milliseconds. These results demonstrate the very good performance of the proposed damper device.
Esta tese apresenta o desenvolvimento de uma metodologia de projeto, a construção de um protótipo e a validação experimental de um amortecedor ativo de vibrações controlado por um atuador piezelétrico. O dispositivo proposto contém um circuito hidráulico constituído por dois foles metálicos flexíveis conectados a um reservatório rígido cheio com um fluido viscoso. Quando um dos foles é conectado a uma estrutura vibratória um fluxo de fluido é forçado através de um orifício variável, produzindo o efeito de amortecimento. O tamanho do orifício é ajustado por um sistema piezelétrico de controle que posiciona um obturador cônico numa cavidade cônica. O amortecedor é modelado pela técnica dos elementos finitos considerando que o corpo da válvula rígido e que existe interação entre o fluido interno e a estrutura flexível dos foles. Este modelo é discretizado utilizando uma formulação Lagrangeana Euleriana. O atuador, composto por uma estrutura metálica flexível que amplifica o deslocamento produzido por uma pilha de cerâmicas piezelétricas, também é modelado pela técnica dos elementos finitos. Foi construído um protótipo do amortecedor e realizados ensaios experimentais com excitações impulsivas e harmônicas, para determinar o comportamento dinâmico e para validar os modelos computacionais desenvolvidos. A relação entre o tamanho do orifício e a correspondente força de amortecimento produzida é obtida tanto a partir de simulações feitas com o modelo computacional, como através de ensaios com o protótipo, para valores do tamanho do orifício fixos e variáveis. Propõe-se o uso de modelos dinâmicos reduzidos para representar a dinâmica do amortecedor. Para garantir que o atuador piezelétrico posicione corretamente o obturador da válvula, foi incorporado ao amortecedor um controlador local clássico tipo PID. O amortecedor ativo foi aplicado a um sistema vibratório que representa o modelo de um quarto de um automóvel. Desenvolveu-se projeto de um controlador liga - desliga e de um controlador fuzzy para controlar a vibração do veículo equipado com o amortecedor ativo. Testes experimentais mostraram que as alterações no valor do coeficiente de amortecimento da suspensão, comandadas pelo controlador global, foram realizadas em tempos inferiores a 10 milisegundos, indicando excelente desempenho do amortecedor proposto.
Doutor em Engenharia Mecânica
Lauzier, Kevin. "Analyse et réduction des vibrations d'un refroidisseur cryogénique pour application spatiale : de la modélisation multiphysique à la commande non linéaire". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI071.
Texto completoEarth observation satellites for meteorological, scientific or military applications sometimes carry infrared imagers. These cameras need to be cooled down to very low temperatures in order to avoid blurry infrared pictures of the Earth, due to the thermal noise of the detector or heat sources nearby. This PhD thesis focuses on a pulse tube cryocooler used in such applications. It deals with induced vibrations as they can destabilize the satellite or make the camera focal plane move. The goals are to understand and reduce the vibrations induced by the pulse tube cryocooler. These PhD works are composed of two main parts. First, the cryocooler is analyzed and modelled to reproduce observed induced vibrations. This global multiphysics model is aimed at identifying dissymmetry, non-linearity and mechanical behaviors which cause vibrations. This approach uses different fields of science such as electromagnetism, mechanics, fluid mechanics and thermodynamics. Sensitivity studies are done and the model is confronted to experiments highlighting measurement tools limits and checking methodologies. Next, vibration reduction using control strategies is studied. The whole control loop is questioned. The improvements proposed concern the vibration sensors, the frequency analysis algorithm, the vibration reduction algorithm and the type of control. Solutions for control, conception and manufacturing resulting from this PhD work offer opportunities to improve the system and lower its cost
Heverly, David E. "Optimal actuator placement and active structure design for control of helicopter airframe vibrations". 2002. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-186/index.html.
Texto completoYu-ChingHsu y 徐鈺青. "Optimal Placement of Sensors and Actuators in Vibration Control of Composite Wings". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5zw3g6.
Texto completo國立成功大學
航空太空工程學系
106
Composite materials have been used extensively in the aviation industry. Although some investigations in static and dynamic performances of composite laminated sandwich materials can be found, it’s rarely seen the research about structural vibration suppression, and less research is based on the composite wing structures. Besides, in the configuration of actuators and sensors, less literature has been mentioned in the form of separate placement. This paper discusses the optimal placement of sensors and actuators. A composite wing with an airfoil function is considered as a model. The actuators and the sensors are glued to any position on the upper and lower wing surfaces. Simulations of active vibration control are done by ANSYS. In optimization problem, a quadratic function related to the vibration amplitude and control input is defined as the objective function. With optimization module in the software, the optimal placement of the sensors and actuators is discussed. In addition, the composite sandwich beam and panel are extra discussed in terms of configuration, and the composite wing with tapered airfoil is verified and discussed.
Halim, Dunant. "Vibration Analysis and Control of Smart Structures". Thesis, 2003. http://hdl.handle.net/1959.13/24886.
Texto completoPhD Doctorate
Halim, Dunant. "Vibration Analysis and Control of Smart Structures". 2003. http://hdl.handle.net/1959.13/24886.
Texto completoPhD Doctorate
陳松村. "On the number and placement of collocated sensors/actuators for vibration control of flexible systems". Thesis, 1992. http://ndltd.ncl.edu.tw/handle/37998229118499958671.
Texto completoChiu, Jia-Shiang y 邱家祥. "Strutural Vibration Control with Self-Sensing Piezoelectric Actuator". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/87327812201701616107.
Texto completo國立成功大學
航空太空工程學系
81
An electromechanical coupling model is developed to predict the natural frequencies of an uniform beam with surface bonded piezoelectric materials. The model includes the electric properties of piezoelectric materials as well as the elastic properties of piezoelectric materials and beam. The electromechanical coupling model is further extended to predict the system modal parameters under piezoelectric actuation. Analysis shows that a stiffening effect from the deflection of the piezoelectric materials it induced under piezoelectric actuation. All analytical predictions are verified by experiments. Active control technique by using the self-sensing piezoelectric actuator is applied to the vibration suppression of flexible structures. Two circuits are implemented to measure the strain and strain rate of the structure for feedback control. The self-sensing actuator with strain or strain rate circuit is shown effective in vibration suppression of a cantilever beam. The strain rate circuit is also applied to the dither motor of a ring laser gyroscope to improve the dithering efficiency.
Huang, Jeng-Jie y 黃鉦傑. "Vibration Control of a Flexible Structure Using MFC Actuator". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6xy2eq.
Texto completo國立臺北科技大學
機電整合研究所
102
This Paper employs a macro-fiber composite (MFC) actuator for vibration suppression in a cantilevered beam due to its higher output force to reject the disturbance. Using a variety of algorithms to calculate the appropriate control action on the root of the cantilever. To achieve the effect of vibration suppression. Skyhook control is relatively simple feedback control, the results have been limited. Therefore, using FxLMS in active adaptive control algorithm has a good effect in vibration suppression control. However, a large number of weights needed to collect more samples to re-identification, it costs a long time to stable. For this drawback, we use notch filter and leaky algorithm. This mothed makes control force stable convergence without divergence. Experimental results show that the algorithm can quickly attenuate vibration of the cantilever.
Tseng, Chuang-Yaw y 曾全佑. "The dynamics of a vibration-control system with a nonlinear actuator". Thesis, 1995. http://ndltd.ncl.edu.tw/handle/03240693844744807635.
Texto completoJeng, Shoei-Po y 鄭水波. "Vibration Control of A Composite Beam with Piezoelectric Sensor and Actuator". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/95451293256017264656.
Texto completoZHAO, SHI-HONG y 趙世宏. "On the actuator dynamics and structural vibration of flight-vehicle control surfaces". Thesis, 1992. http://ndltd.ncl.edu.tw/handle/21253021306230964814.
Texto completoChen, Jui-Lung y 陳瑞龍. "Vibration control of a cantilever pipe conveying fluid using a piezoelectric inertia actuator". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/43484796412423380470.
Texto completoDarivandi, Shoushtari Neda. "Optimal Active Control of Flexible Structures Applying Piezoelectric Actuators". Thesis, 2013. http://hdl.handle.net/10012/7459.
Texto completoViswamurthy, S. R. "Piezoceramic Dynamic Hysteresis Effects On Helicopter Vibration Control Using Multiple Trailing-Edge Flaps". Thesis, 2007. http://hdl.handle.net/2005/561.
Texto completo