Dépouillements

Model reduction of large-scale discrete plants with specified frequency domain balanced structure in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 01 p. Titre : Model reduction of large-scale discrete plants with specified frequency domain balanced structure Type de document : texte imprimé Année de publication : 2010 Article en page(s) : 01 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : industrial  plants Résumé : This work presents a commentary of the article published by A. Zadegan and A. Zilouchian (2005, ASME J. Dyn. Syst. Meas., Control, 127 , pp. 486–498). We show their order reduction method is not always true and may lead to inaccurate results and is therefore erroneous. A framework for solving the problem is also suggested. Note de contenu : Discussion: “Model Reduction of Large-Scale Discrete Plants With Specified Frequency Domain Balanced Structure” (Zadegan, A., and Zilouchian, A., 2005, ASME J. Dyn. Syst. Meas., Control, 127, pp. 486–498) DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Model reduction of large-scale discrete plants with specified frequency domain balanced structure [texte imprimé] . - 2010 . - 01 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 01 p. Mots-clés : industrial  plants Résumé : This work presents a commentary of the article published by A. Zadegan and A. Zilouchian (2005, ASME J. Dyn. Syst. Meas., Control, 127 , pp. 486–498). We show their order reduction method is not always true and may lead to inaccurate results and is therefore erroneous. A framework for solving the problem is also suggested. Note de contenu : Discussion: “Model Reduction of Large-Scale Discrete Plants With Specified Frequency Domain Balanced Structure” (Zadegan, A., and Zilouchian, A., 2005, ASME J. Dyn. Syst. Meas., Control, 127, pp. 486–498) DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

A review of feedforward control approaches in nanopositioning for high-speed SPM / Garrett M. Clayton in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 19 p. Titre : A review of feedforward control approaches in nanopositioning for high-speed SPM Type de document : texte imprimé Auteurs : Garrett M. Clayton, Auteur ; Szuchi Tien, Auteur ; Kam K. Leang, Auteur Année de publication : 2010 Article en page(s) : 19 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : scanning  probe  microscopy;  errors;  feedforward  control;  probes;  imaging Résumé : Control can enable high-bandwidth nanopositioning needed to increase the operating speed of scanning probe microscopes (SPMs). High-speed SPMs can substantially impact the throughput of a wide range of emerging nanosciences and nanotechnologies. In particular, inversion-based control can find the feedforward input needed to account for the positioning dynamics and, thus, achieve the required precision and bandwidth. This article reviews inversion-based feedforward approaches used for high-speed SPMs such as optimal inversion that accounts for model uncertainty and inversion-based iterative control for repetitive applications. The article establishes connections to other existing methods such as zero-phase-error-tracking feedforward and robust feedforward. Additionally, the article reviews the use of feedforward in emerging applications such as SPM-based nanoscale combinatorial-science studies, image-based control for subnanometer-scale studies, and imaging of large soft biosamples with SPMs. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] A review of feedforward control approaches in nanopositioning for high-speed SPM [texte imprimé] / Garrett M. Clayton, Auteur ; Szuchi Tien, Auteur ; Kam K. Leang, Auteur . - 2010 . - 19 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 19 p. Mots-clés : scanning  probe  microscopy;  errors;  feedforward  control;  probes;  imaging Résumé : Control can enable high-bandwidth nanopositioning needed to increase the operating speed of scanning probe microscopes (SPMs). High-speed SPMs can substantially impact the throughput of a wide range of emerging nanosciences and nanotechnologies. In particular, inversion-based control can find the feedforward input needed to account for the positioning dynamics and, thus, achieve the required precision and bandwidth. This article reviews inversion-based feedforward approaches used for high-speed SPMs such as optimal inversion that accounts for model uncertainty and inversion-based iterative control for repetitive applications. The article establishes connections to other existing methods such as zero-phase-error-tracking feedforward and robust feedforward. Additionally, the article reviews the use of feedforward in emerging applications such as SPM-based nanoscale combinatorial-science studies, image-based control for subnanometer-scale studies, and imaging of large soft biosamples with SPMs. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Nanoscale friction dynamic modeling / Fakhreddine Landolsi in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Titre : Nanoscale friction dynamic modeling Type de document : texte imprimé Auteurs : Fakhreddine Landolsi, Auteur ; Ghorbel, Fathi H., Auteur ; Jun Lou, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : force;  friction;  motion;  nanoscale  phenomena;  stick-slip Résumé : Friction and system models are fundamentally coupled. In fact, the success of models in predicting experimental results depends highly on the modeling of friction. This is true at the atomic scale where the nanoscale friction depends on a large set of parameters. This paper presents a novel nanoscale friction model based on the bristle interpretation of single asperity contact. This interpretation is adopted after a review of dynamic friction models representing stick-slip motion in macrotribology literature. The proposed model uses state variables and introduces a generalized bristle deflection. Jumping mechanisms are implemented in order to take into account the instantaneous jumps observed during 2D stick-slip phenomena. The model is dynamic and Lipchitz, which makes it suitable for future control implementation. Friction force microscope scans of a muscovite mica sample were conducted in order to determine numerical values of the different model parameters. The simulated and experimental results are then compared in order to show the efficacy of the proposed model. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Nanoscale friction dynamic modeling [texte imprimé] / Fakhreddine Landolsi, Auteur ; Ghorbel, Fathi H., Auteur ; Jun Lou, Auteur . - 2010 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Mots-clés : force;  friction;  motion;  nanoscale  phenomena;  stick-slip Résumé : Friction and system models are fundamentally coupled. In fact, the success of models in predicting experimental results depends highly on the modeling of friction. This is true at the atomic scale where the nanoscale friction depends on a large set of parameters. This paper presents a novel nanoscale friction model based on the bristle interpretation of single asperity contact. This interpretation is adopted after a review of dynamic friction models representing stick-slip motion in macrotribology literature. The proposed model uses state variables and introduces a generalized bristle deflection. Jumping mechanisms are implemented in order to take into account the instantaneous jumps observed during 2D stick-slip phenomena. The model is dynamic and Lipchitz, which makes it suitable for future control implementation. Friction force microscope scans of a muscovite mica sample were conducted in order to determine numerical values of the different model parameters. The simulated and experimental results are then compared in order to show the efficacy of the proposed model. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Design and analysis of discrete-time repetitive control for scanning probe microscopes / Ugur Aridogan in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Titre : Design and analysis of discrete-time repetitive control for scanning probe microscopes Type de document : texte imprimé Auteurs : Ugur Aridogan, Auteur ; Yingfeng Shan, Auteur ; Kam K. Leang, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : dynamics  (mechanics);  stability;  atomic  force  microscopy;  control  equipment;  motion;  simulation;  scanning  probe  microscopy;  design;  errors;  feedback;  robustness;  steady  state;  imaging Résumé : This paper studies repetitive control (RC) with linear phase lead compensation to precisely track periodic trajectories in piezo-based scanning probe microscopes (SPMs). Quite often, the lateral scanning motion in SPMs during imaging or nanofabrication is periodic. Dynamic and hysteresis effects in the piezoactuator cause significant tracking error. To minimize the tracking error, commercial SPMs commonly use proportional-integral-derivative (PID) feedback controllers; however, the residual error of PID control can be excessively large, especially at high scan rates. In addition, the error repeats from one operating cycle to the next. To account for the periodic tracking error, a discrete-time RC is designed, analyzed, and implemented on an atomic force microscope (AFM). The advantages of RC include straightforward digital implementation and it can be plugged into an existing feedback control loop, such as PID, to enhance performance. The proposed RC incorporates two phase lead compensators to ensure robustness and minimize the steady-state tracking error. Simulation and experimental results from an AFM system compare the performance among (1) PID, (2) standard RC, and (3) the modified RC with phase lead compensation. The results show that the latter reduces the steady-state tracking error to less than 2% at 25 Hz scan rate, an over 80% improvement compared with PID control. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Design and analysis of discrete-time repetitive control for scanning probe microscopes [texte imprimé] / Ugur Aridogan, Auteur ; Yingfeng Shan, Auteur ; Kam K. Leang, Auteur . - 2010 . - 12 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Mots-clés : dynamics  (mechanics);  stability;  atomic  force  microscopy;  control  equipment;  motion;  simulation;  scanning  probe  microscopy;  design;  errors;  feedback;  robustness;  steady  state;  imaging Résumé : This paper studies repetitive control (RC) with linear phase lead compensation to precisely track periodic trajectories in piezo-based scanning probe microscopes (SPMs). Quite often, the lateral scanning motion in SPMs during imaging or nanofabrication is periodic. Dynamic and hysteresis effects in the piezoactuator cause significant tracking error. To minimize the tracking error, commercial SPMs commonly use proportional-integral-derivative (PID) feedback controllers; however, the residual error of PID control can be excessively large, especially at high scan rates. In addition, the error repeats from one operating cycle to the next. To account for the periodic tracking error, a discrete-time RC is designed, analyzed, and implemented on an atomic force microscope (AFM). The advantages of RC include straightforward digital implementation and it can be plugged into an existing feedback control loop, such as PID, to enhance performance. The proposed RC incorporates two phase lead compensators to ensure robustness and minimize the steady-state tracking error. Simulation and experimental results from an AFM system compare the performance among (1) PID, (2) standard RC, and (3) the modified RC with phase lead compensation. The results show that the latter reduces the steady-state tracking error to less than 2% at 25 Hz scan rate, an over 80% improvement compared with PID control. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

DMCMN / Georg E. Fantner in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 13 p. Titre : DMCMN : in depth characterization and control of AFM cantilevers with integrated sensing and actuation Type de document : texte imprimé Auteurs : Georg E. Fantner, Auteur ; Daniel J. Burns, Auteur ; Angela M. Belcher, Auteur Année de publication : 2010 Article en page(s) : 13 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : atomic  force  microscopy;  actuators;  cantilevers;  deflection;  imaging Résumé : New developments in MEMS (microelectromechanical systems) fabrication allowed the development of new types of atomic force microscopy (AFM) sensor with integrated readout circuit and actuator built in on the cantilever. Such a fully instrumented cantilever allows a much more direct measurement and actuation of the cantilever motion and interaction with the sample. This technology is expected to not only allow for high speed imaging but also the miniaturization of AFMs. Based on the complexity of these integrated MEMS devices, a thorough understanding of their behavior and a specialized controls approach is needed to make the most use out of this new technology. In this paper we investigate the intrinsic properties of such MEMS cantilevers and develop a combined approach for sensing and control, optimized for high speed detection and actuation. Further developments based on the results presented in this paper will help to expand the use of atomic force microscopy to a broad range of everyday applications in industrial process control and clinical diagnostics. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] DMCMN : in depth characterization and control of AFM cantilevers with integrated sensing and actuation [texte imprimé] / Georg E. Fantner, Auteur ; Daniel J. Burns, Auteur ; Angela M. Belcher, Auteur . - 2010 . - 13 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 13 p. Mots-clés : atomic  force  microscopy;  actuators;  cantilevers;  deflection;  imaging Résumé : New developments in MEMS (microelectromechanical systems) fabrication allowed the development of new types of atomic force microscopy (AFM) sensor with integrated readout circuit and actuator built in on the cantilever. Such a fully instrumented cantilever allows a much more direct measurement and actuation of the cantilever motion and interaction with the sample. This technology is expected to not only allow for high speed imaging but also the miniaturization of AFMs. Based on the complexity of these integrated MEMS devices, a thorough understanding of their behavior and a specialized controls approach is needed to make the most use out of this new technology. In this paper we investigate the intrinsic properties of such MEMS cantilevers and develop a combined approach for sensing and control, optimized for high speed detection and actuation. Further developments based on the results presented in this paper will help to expand the use of atomic force microscopy to a broad range of everyday applications in industrial process control and clinical diagnostics. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

An iterative-based feedforward-feedback control approach to high-speed atomic force microscope imaging / Ying Wu in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 09 p. Titre : An iterative-based feedforward-feedback control approach to high-speed atomic force microscope imaging Type de document : texte imprimé Auteurs : Ying Wu, Auteur ; Qingze, Zou, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : atomic  force  microscopy;  design;  errors;  feedback;  feedforward  control;  imaging;  iterative  learning  control Résumé : This article presents an iterative-based feedforward-feedback control approach to achieve high-speed atomic force microscope (AFM) imaging. AFM-imaging requires precision positioning of the probe relative to the sample in all x-y-z axes directions. Particularly, this article is focused on the vertical z-axis positioning. Recently, a current-cycle-feedback iterative-learning-control (CCF-ILC) approach has been developed for precision tracking of a given desired trajectory (even when the desired trajectory is unknown), which can be applied to achieve precision tracking of sample profile on one scanline. In this article, we extend this CCF-ILC approach to imaging of entire sample area. The main contribution of this article is the convergence analysis and the use of the CCF-ILC approach for output tracking in the presence of desired trajectory varation between iterations—the sample topography variations between adjacent scanlines. For general case where the desired trajectory variation occurs between any two successive iterations, the convergence (stability) of the CCF-ILC system is addressed and the allowable size of desired trajectory variation is quantified. The performance improvement achieved by using the CCF-ILC approach is discussed by comparing the tracking error of using the CCF-ILC technique to that of using feedback control alone. The efficacy of the proposed CCF-ILC control approach is illustrated by implementing it to the z-axis control during AFM-imaging. Experimental results are presented to show that the AFM-imaging speed can be substantially increased. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] An iterative-based feedforward-feedback control approach to high-speed atomic force microscope imaging [texte imprimé] / Ying Wu, Auteur ; Qingze, Zou, Auteur . - 2010 . - 09 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 09 p. Mots-clés : atomic  force  microscopy;  design;  errors;  feedback;  feedforward  control;  imaging;  iterative  learning  control Résumé : This article presents an iterative-based feedforward-feedback control approach to achieve high-speed atomic force microscope (AFM) imaging. AFM-imaging requires precision positioning of the probe relative to the sample in all x-y-z axes directions. Particularly, this article is focused on the vertical z-axis positioning. Recently, a current-cycle-feedback iterative-learning-control (CCF-ILC) approach has been developed for precision tracking of a given desired trajectory (even when the desired trajectory is unknown), which can be applied to achieve precision tracking of sample profile on one scanline. In this article, we extend this CCF-ILC approach to imaging of entire sample area. The main contribution of this article is the convergence analysis and the use of the CCF-ILC approach for output tracking in the presence of desired trajectory varation between iterations—the sample topography variations between adjacent scanlines. For general case where the desired trajectory variation occurs between any two successive iterations, the convergence (stability) of the CCF-ILC system is addressed and the allowable size of desired trajectory variation is quantified. The performance improvement achieved by using the CCF-ILC approach is discussed by comparing the tracking error of using the CCF-ILC technique to that of using feedback control alone. The efficacy of the proposed CCF-ILC control approach is illustrated by implementing it to the z-axis control during AFM-imaging. Experimental results are presented to show that the AFM-imaging speed can be substantially increased. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Towards automated nanoassembly with the atomic force microscope / Florian Krohs in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Titre : Towards automated nanoassembly with the atomic force microscope : a versatile drift compensation procedure Type de document : texte imprimé Auteurs : Florian Krohs, Auteur ; Cagdas Onal, Auteur ; Sitti, Metin, Auteur Année de publication : 2010 Article en page(s) : 08 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : sensors;  atomic  force  microscopy;  particulate  matter;  nanoparticles;  algorithms;  displacement;  filters Résumé : While the atomic force microscope (AFM) was mainly developed to image the topography of a sample, it has been discovered as a powerful tool also for nanomanipulation applications within the last decade. A variety of different manipulation types exists, ranging from dip-pen and mechanical lithography to assembly of nano-objects such as carbon nanotubes (CNTs), deoxyribonucleic acid (DNA) strains, or nanospheres. The latter, the assembly of nano-objects, is a very promising technique for prototyping nanoelectronical devices that are composed of DNA-based nanowires, CNTs, etc. But, pushing nano-objects in the order of a few nanometers nowadays remains a very challenging, labor-intensive task that requires frequent human intervention. To increase throughput of AFM-based nanomanipulation, automation can be considered as a long-term goal. However, automation is impeded by spatial uncertainties existing in every AFM system. This article focuses on thermal drift, which is a crucial error source for automating AFM-based nanoassembly, since it implies a varying, spatial displacement between AFM probe and sample. A novel, versatile drift estimation method based on Monte Carlo localization is presented and experimental results obtained on different AFM systems illustrate that the developed algorithm is able to estimate thermal drift inside an AFM reliably even with highly unstructured samples and inside inhomogeneous environments. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Towards automated nanoassembly with the atomic force microscope : a versatile drift compensation procedure [texte imprimé] / Florian Krohs, Auteur ; Cagdas Onal, Auteur ; Sitti, Metin, Auteur . - 2010 . - 08 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Mots-clés : sensors;  atomic  force  microscopy;  particulate  matter;  nanoparticles;  algorithms;  displacement;  filters Résumé : While the atomic force microscope (AFM) was mainly developed to image the topography of a sample, it has been discovered as a powerful tool also for nanomanipulation applications within the last decade. A variety of different manipulation types exists, ranging from dip-pen and mechanical lithography to assembly of nano-objects such as carbon nanotubes (CNTs), deoxyribonucleic acid (DNA) strains, or nanospheres. The latter, the assembly of nano-objects, is a very promising technique for prototyping nanoelectronical devices that are composed of DNA-based nanowires, CNTs, etc. But, pushing nano-objects in the order of a few nanometers nowadays remains a very challenging, labor-intensive task that requires frequent human intervention. To increase throughput of AFM-based nanomanipulation, automation can be considered as a long-term goal. However, automation is impeded by spatial uncertainties existing in every AFM system. This article focuses on thermal drift, which is a crucial error source for automating AFM-based nanoassembly, since it implies a varying, spatial displacement between AFM probe and sample. A novel, versatile drift estimation method based on Monte Carlo localization is presented and experimental results obtained on different AFM systems illustrate that the developed algorithm is able to estimate thermal drift inside an AFM reliably even with highly unstructured samples and inside inhomogeneous environments. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Modeling piezoresponse force microscopy for low-dimensional material characterization / Amin Salehi-Khojin in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Titre : Modeling piezoresponse force microscopy for low-dimensional material characterization : theory and experiment Type de document : texte imprimé Auteurs : Amin Salehi-Khojin, Auteur ; Saeid Bashash, Auteur ; Jalili, Nader, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : theorems  (mathematics);  force;  electric  potential;  motion;  piezoelectric  materials;  equations  of  motion;  materials  properties;  differential  equations;  modeling;  vibration;  microscopy;  elastic  constants;  frequency;  frequency  response;  parameter  estimation;  stiffness Résumé : Piezoresponse force microscopy (PFM) is an atomic force microscopy-based approach utilized for measuring local properties of piezoelectric materials. The objective of this study is to propose a practical framework for simultaneous estimation of the local stiffness and piezoelectric properties of materials. For this, the governing equation of motion of a vertical PFM is derived at a given point on the sample. Using the expansion theorem, the governing ordinary differential equations of the system and their state-space representation are derived under applied external voltage. For the proof of the concept, the results obtained from both frequency and step responses of a PFM experiment are utilized to simultaneously identify the microcantilever parameters along with local spring constant and piezoelectric coefficient of a periodically poled lithium niobate sample. In this regard, a new parameter estimation strategy is developed for modal identification of system parameters under general frequency response. Results indicate good agreements between the identified model and the experimental data using the proposed modeling and identification framework. This method can be particularly applied for accurate characterization of mechanical and piezoelectric properties of biological species and cells. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Modeling piezoresponse force microscopy for low-dimensional material characterization : theory and experiment [texte imprimé] / Amin Salehi-Khojin, Auteur ; Saeid Bashash, Auteur ; Jalili, Nader, Auteur . - 2010 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Mots-clés : theorems  (mathematics);  force;  electric  potential;  motion;  piezoelectric  materials;  equations  of  motion;  materials  properties;  differential  equations;  modeling;  vibration;  microscopy;  elastic  constants;  frequency;  frequency  response;  parameter  estimation;  stiffness Résumé : Piezoresponse force microscopy (PFM) is an atomic force microscopy-based approach utilized for measuring local properties of piezoelectric materials. The objective of this study is to propose a practical framework for simultaneous estimation of the local stiffness and piezoelectric properties of materials. For this, the governing equation of motion of a vertical PFM is derived at a given point on the sample. Using the expansion theorem, the governing ordinary differential equations of the system and their state-space representation are derived under applied external voltage. For the proof of the concept, the results obtained from both frequency and step responses of a PFM experiment are utilized to simultaneously identify the microcantilever parameters along with local spring constant and piezoelectric coefficient of a periodically poled lithium niobate sample. In this regard, a new parameter estimation strategy is developed for modal identification of system parameters under general frequency response. Results indicate good agreements between the identified model and the experimental data using the proposed modeling and identification framework. This method can be particularly applied for accurate characterization of mechanical and piezoelectric properties of biological species and cells. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Special issue on dynamic modeling, control and manipulation at the nanoscale / Jalili, Nader in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 02 p. Titre : Special issue on dynamic modeling, control and manipulation at the nanoscale Type de document : texte imprimé Auteurs : Jalili, Nader, Auteur ; Laxman Saggere, Auteur ; Arvind Raman, Auteur Année de publication : 2010 Article en page(s) : 02 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : nanoscale;  dynamic  modeling Résumé : Most of today's emerging nanotechnological applications such as nanoelectromechanical systems require comprehensive modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. An important task amongst many challenging aspects of “nanoscale” manipulation and control design is to overcome the added complexity of uncertainties and nonlinearities that are unique to nanoscale. This added complexity combined with the sub-nanometer precision requirement calls for development of fundamentally new techniques and controllers for these applications. In an effort to respond to such demanding needs for new directions in modeling and control at the nanoscale, this special issue attempts to bring together the current advances in this area and target current research and development efforts in nanoscale control and manipulation techniques including scanning probe microscopy (SPM) systems as well as nanorobotic manipulation. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Special issue on dynamic modeling, control and manipulation at the nanoscale [texte imprimé] / Jalili, Nader, Auteur ; Laxman Saggere, Auteur ; Arvind Raman, Auteur . - 2010 . - 02 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 02 p. Mots-clés : nanoscale;  dynamic  modeling Résumé : Most of today's emerging nanotechnological applications such as nanoelectromechanical systems require comprehensive modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. An important task amongst many challenging aspects of “nanoscale” manipulation and control design is to overcome the added complexity of uncertainties and nonlinearities that are unique to nanoscale. This added complexity combined with the sub-nanometer precision requirement calls for development of fundamentally new techniques and controllers for these applications. In an effort to respond to such demanding needs for new directions in modeling and control at the nanoscale, this special issue attempts to bring together the current advances in this area and target current research and development efforts in nanoscale control and manipulation techniques including scanning probe microscopy (SPM) systems as well as nanorobotic manipulation. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Desired compensation adaptive robust control / Yao, Bin in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Titre : Desired compensation adaptive robust control Type de document : texte imprimé Auteurs : Yao, Bin, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : adaptive  robust  control;  nonlinear  systems Résumé : A desired compensation adaptive robust control (DCARC) framework is presented for nonlinear systems having both parametric uncertainties and uncertain nonlinearities. The paper first considers a class of higher order nonlinear systems transformable to a normal form with matched model uncertainties. For this class of uncertain systems, the desired values of all states for tracking a known desired trajectory can be predetermined and the usual desired compensation concept can be used to synthesize DCARC laws. The paper then focuses on systems with unmatched model uncertainties, in which the desired values of the intermediate state variables for perfect output tracking of a known desired trajectory cannot be predetermined. A novel way of formulating desired compensation concept is proposed and a DCARC backstepping design is developed to overcome the design difficulties associated with unmatched model uncertainties. The proposed DCARC framework has the unique feature that the adaptive model compensation and the regressor depend on the reference output trajectory and on-line parameter estimates only. Such a structure has several implementation advantages. First, the adaptive model compensation is always bounded when projection type adaption law is used, and thus does not affect the closed-loop system stability. As a result, the interaction between the parameter adaptation and the robust control law is reduced, which may facilitate the controller gain tuning process considerably. Second, the effect of measurement noise on the adaptive model compensation and on the parameter adaptation law is minimized. Consequently, a faster adaptation rate can be chosen in implementation to speed up the transient response and to improve overall tracking performance. These claims have been verified in the comparative experimental studies of several applications. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Desired compensation adaptive robust control [texte imprimé] / Yao, Bin, Auteur . - 2010 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Mots-clés : adaptive  robust  control;  nonlinear  systems Résumé : A desired compensation adaptive robust control (DCARC) framework is presented for nonlinear systems having both parametric uncertainties and uncertain nonlinearities. The paper first considers a class of higher order nonlinear systems transformable to a normal form with matched model uncertainties. For this class of uncertain systems, the desired values of all states for tracking a known desired trajectory can be predetermined and the usual desired compensation concept can be used to synthesize DCARC laws. The paper then focuses on systems with unmatched model uncertainties, in which the desired values of the intermediate state variables for perfect output tracking of a known desired trajectory cannot be predetermined. A novel way of formulating desired compensation concept is proposed and a DCARC backstepping design is developed to overcome the design difficulties associated with unmatched model uncertainties. The proposed DCARC framework has the unique feature that the adaptive model compensation and the regressor depend on the reference output trajectory and on-line parameter estimates only. Such a structure has several implementation advantages. First, the adaptive model compensation is always bounded when projection type adaption law is used, and thus does not affect the closed-loop system stability. As a result, the interaction between the parameter adaptation and the robust control law is reduced, which may facilitate the controller gain tuning process considerably. Second, the effect of measurement noise on the adaptive model compensation and on the parameter adaptation law is minimized. Consequently, a faster adaptation rate can be chosen in implementation to speed up the transient response and to improve overall tracking performance. These claims have been verified in the comparative experimental studies of several applications. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

On the generalized frequency response functions of volterra systems / Xingjian Jing in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Titre : On the generalized frequency response functions of volterra systems Type de document : texte imprimé Auteurs : Xingjian Jing, Auteur ; Ziqiang Lang, Auteur Année de publication : 2010 Article en page(s) : 08 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : volterra  Systems Résumé : The generalized frequency response function (GFRF) for Volterra systems described by the nonlinear autoregressive with exogenous input model is determined by a new mapping function based on its parametric characteristic. The nth-order GFRF can now be directly determined in terms of the first order GFRF, which represents the linear component of the system, and model parameters, which define system nonlinearities. Some new properties of the GFRFs are therefore developed. These results can analytically reveal the linear and nonlinear effects on system frequency response functions, and also demonstrate the relationship between convergence of system Volterra series expansion and model parameters. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] On the generalized frequency response functions of volterra systems [texte imprimé] / Xingjian Jing, Auteur ; Ziqiang Lang, Auteur . - 2010 . - 08 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Mots-clés : volterra  Systems Résumé : The generalized frequency response function (GFRF) for Volterra systems described by the nonlinear autoregressive with exogenous input model is determined by a new mapping function based on its parametric characteristic. The nth-order GFRF can now be directly determined in terms of the first order GFRF, which represents the linear component of the system, and model parameters, which define system nonlinearities. Some new properties of the GFRFs are therefore developed. These results can analytically reveal the linear and nonlinear effects on system frequency response functions, and also demonstrate the relationship between convergence of system Volterra series expansion and model parameters. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Position tracking control of a miniature water hydraulic rotary actuator / Russell Sindrey in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Titre : Position tracking control of a miniature water hydraulic rotary actuator Type de document : texte imprimé Auteurs : Russell Sindrey, Auteur ; Gary M. Bone, Auteur Année de publication : 2010 Article en page(s) : 08 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : flow  (dynamics);  control  equipment;  actuators;  valves;  cylinders;  robustness;  water Résumé : Over the past 20 years, research in the field of miniature actuators has increased substantially due to advances in smart material fabrication, semiconductor chip technology, and computer processing capability. Hydraulic cylinders offer many potential benefits as miniature actuators, including high power-to-weight ratio, mechanical stiffness, smooth motion, and the potential for high positional accuracy. Despite their benefits, the control of hydraulic cylinders with bore diameters under 10 mm has not been previously studied. The most significant obstacle to implementing the use of miniature cylinders is the unavailability of off-the-shelf proportional valves that are compatible with hydraulic fluid and precise enough for the position control task. In this paper, two novel model-based nonlinear control strategies are presented for the position control of a rotary actuator powered by two 4 mm bore diameter cylinders. Four off-the-shelf, low cost, 2/2 on/off miniature solenoid valves were used to control the flow of water to and from the cylinder chambers. A novel valve coordination scheme is also presented that allows the on/off valves to approximate the behavior of a proportional valve. The tracking performance of each controller was experimentally tested and both controllers were found to achieve steady-state positioning accuracies of the cylinders within ±0.07 mm. The robustness of the controllers to changes in payload mass and vertical orientation was also tested. Results from several experiments are presented and compared. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Position tracking control of a miniature water hydraulic rotary actuator [texte imprimé] / Russell Sindrey, Auteur ; Gary M. Bone, Auteur . - 2010 . - 08 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 08 p. Mots-clés : flow  (dynamics);  control  equipment;  actuators;  valves;  cylinders;  robustness;  water Résumé : Over the past 20 years, research in the field of miniature actuators has increased substantially due to advances in smart material fabrication, semiconductor chip technology, and computer processing capability. Hydraulic cylinders offer many potential benefits as miniature actuators, including high power-to-weight ratio, mechanical stiffness, smooth motion, and the potential for high positional accuracy. Despite their benefits, the control of hydraulic cylinders with bore diameters under 10 mm has not been previously studied. The most significant obstacle to implementing the use of miniature cylinders is the unavailability of off-the-shelf proportional valves that are compatible with hydraulic fluid and precise enough for the position control task. In this paper, two novel model-based nonlinear control strategies are presented for the position control of a rotary actuator powered by two 4 mm bore diameter cylinders. Four off-the-shelf, low cost, 2/2 on/off miniature solenoid valves were used to control the flow of water to and from the cylinder chambers. A novel valve coordination scheme is also presented that allows the on/off valves to approximate the behavior of a proportional valve. The tracking performance of each controller was experimentally tested and both controllers were found to achieve steady-state positioning accuracies of the cylinders within ±0.07 mm. The robustness of the controllers to changes in payload mass and vertical orientation was also tested. Results from several experiments are presented and compared. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Frequency tuning of a disk resonator gyro via mass matrix perturbation / David Schwartz in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Titre : Frequency tuning of a disk resonator gyro via mass matrix perturbation Type de document : texte imprimé Auteurs : David Schwartz, Auteur ; Dong Joon Kim, Auteur ; Robert T. M'Closkey, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : sensors;  magnets;  actuators;  algorithms;  disks;  fittings;  frequency;  frequency  response;  shapes Résumé : Electrostatic tuning of the resonant modes in microelectromechanical vibratory gyroscopes is often suggested as a means for compensating manufacturing aberrations that produce detuned resonances. In high performance sensors, however, this approach places very stringent requirements on the stability of the bias voltages used for tuning. Furthermore, the bias voltage stability must be maintained over the operating environment, especially with regard to temperature variations. An alternative solution to this problem is to use mass perturbations of the sensor’s resonant structure for resonant mode tuning. This paper presents a new mass perturbation technique that only relies on the sensor’s integrated actuators and pick-offs to guide the mass perturbation process. The algorithm is amenable to automation and eliminates the requirement that the modal nodes of the resonator be identified by direct measurement. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Frequency tuning of a disk resonator gyro via mass matrix perturbation [texte imprimé] / David Schwartz, Auteur ; Dong Joon Kim, Auteur ; Robert T. M'Closkey, Auteur . - 2010 . - 12 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Mots-clés : sensors;  magnets;  actuators;  algorithms;  disks;  fittings;  frequency;  frequency  response;  shapes Résumé : Electrostatic tuning of the resonant modes in microelectromechanical vibratory gyroscopes is often suggested as a means for compensating manufacturing aberrations that produce detuned resonances. In high performance sensors, however, this approach places very stringent requirements on the stability of the bias voltages used for tuning. Furthermore, the bias voltage stability must be maintained over the operating environment, especially with regard to temperature variations. An alternative solution to this problem is to use mass perturbations of the sensor’s resonant structure for resonant mode tuning. This paper presents a new mass perturbation technique that only relies on the sensor’s integrated actuators and pick-offs to guide the mass perturbation process. The algorithm is amenable to automation and eliminates the requirement that the modal nodes of the resonator be identified by direct measurement. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

On the control of engine start/stop dynamics in a hybrid electric vehicle / Canova, Marcello in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Titre : On the control of engine start/stop dynamics in a hybrid electric vehicle Type de document : texte imprimé Auteurs : Canova, Marcello, Auteur ; Yann Guezennec, Auteur ; Steve Yurkovich, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : torque;  engines Résumé : The starter/alternator technology is considered an easily realizable hybrid electric vehicle (HEV) configuration to achieve significant fuel economy without compromising consumer acceptability. Several examples can be found in production or near-production vehicles, with implementation based on a spark ignition (SI) engine coupled with either a belted starter/alternator (BSA) or an integrated starter/alternator (ISA). One of the many challenges in successfully developing a starter/alternator HEV is to achieve engine start and stop operations with minimum passenger discomfort. This requires control of the electric motor to start and stop the engine quickly and smoothly, without compromising the vehicle noise, vibration, and harshness signature. The issue becomes more critical in the case of diesel hybrids, as the peak compression torque is much larger than in SI engines. This paper documents the results of a research activity focused on the control of the start and stop dynamics of a HEV with a belted starter/alternator. The work was conducted on a production 1.9 l common-rail diesel engine coupled to a 10.6 kW permanent magnet motor. The system is part of a series/parallel HEV powertrain, designed to fit a midsize prototype sport utility vehicle. A preliminary experimental investigation was done to assess the feasibility of the concept and to partially characterize the system. This facilitated the design of a control-oriented nonlinear model of the system dynamics and its validation on the complete HEV hardware. Model-based control techniques were then applied to design a controller for the belted starter/alternator, ensuring quick and smooth engine start operations. The final control design has been implemented on the vehicle. The research outcomes demonstrated that the BSA is effective in starting the diesel engine quickly and with very limited vibration and noise. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] On the control of engine start/stop dynamics in a hybrid electric vehicle [texte imprimé] / Canova, Marcello, Auteur ; Yann Guezennec, Auteur ; Steve Yurkovich, Auteur . - 2010 . - 12 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 12 p. Mots-clés : torque;  engines Résumé : The starter/alternator technology is considered an easily realizable hybrid electric vehicle (HEV) configuration to achieve significant fuel economy without compromising consumer acceptability. Several examples can be found in production or near-production vehicles, with implementation based on a spark ignition (SI) engine coupled with either a belted starter/alternator (BSA) or an integrated starter/alternator (ISA). One of the many challenges in successfully developing a starter/alternator HEV is to achieve engine start and stop operations with minimum passenger discomfort. This requires control of the electric motor to start and stop the engine quickly and smoothly, without compromising the vehicle noise, vibration, and harshness signature. The issue becomes more critical in the case of diesel hybrids, as the peak compression torque is much larger than in SI engines. This paper documents the results of a research activity focused on the control of the start and stop dynamics of a HEV with a belted starter/alternator. The work was conducted on a production 1.9 l common-rail diesel engine coupled to a 10.6 kW permanent magnet motor. The system is part of a series/parallel HEV powertrain, designed to fit a midsize prototype sport utility vehicle. A preliminary experimental investigation was done to assess the feasibility of the concept and to partially characterize the system. This facilitated the design of a control-oriented nonlinear model of the system dynamics and its validation on the complete HEV hardware. Model-based control techniques were then applied to design a controller for the belted starter/alternator, ensuring quick and smooth engine start operations. The final control design has been implemented on the vehicle. The research outcomes demonstrated that the BSA is effective in starting the diesel engine quickly and with very limited vibration and noise. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

Self-sensing active magnetic dampers for vibration control / Angelo Bonfitto in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Titre : Self-sensing active magnetic dampers for vibration control Type de document : texte imprimé Auteurs : Angelo Bonfitto, Auteur ; Xavier De Lépine, Auteur ; Mario Silvagni, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : dynamics  (mechanics);  force;  electric  potential;  control  equipment;  vibration  control;  degrees  of  freedom  mechanics);  actuators;  dampers;  damping;  design;  modeling;  rotors;  closed  loop  systems;  electromagnets;  open  loop  systems;  sensitivity  analysis;  state  feedback;  stiffness Résumé : The aim of this paper is to investigate the potential of a self-sensing strategy in the case of an electromagnetic damper for the vibration control of flexible structures and rotors. The study has been performed in the case of a single degree of freedom mechanical oscillator actuated by a couple of electromagnets. The self-sensing system is based on a Luenberger observer. Two sets of parameters have been used: nominal ones (based on simplifications on the actuator model) and identified ones. In the latter case, the parameters of the electromechanical model used in the observer are identified starting from the open-loop system response. The observed states are used to close a state-feedback loop with the objective of increasing the damping of the system. The results show that the damping performance are good in both cases, although much better in the second one. Furthermore, the good correlation between the closed-loop model response and the experimental results validates the modeling, the identification procedure, the control design, and its implementation. The paper concludes on a sensitivity analysis, in which the influence of the model parameters on the closed-loop response is shown. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] Self-sensing active magnetic dampers for vibration control [texte imprimé] / Angelo Bonfitto, Auteur ; Xavier De Lépine, Auteur ; Mario Silvagni, Auteur . - 2010 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 07 p. Mots-clés : dynamics  (mechanics);  force;  electric  potential;  control  equipment;  vibration  control;  degrees  of  freedom  mechanics);  actuators;  dampers;  damping;  design;  modeling;  rotors;  closed  loop  systems;  electromagnets;  open  loop  systems;  sensitivity  analysis;  state  feedback;  stiffness Résumé : The aim of this paper is to investigate the potential of a self-sensing strategy in the case of an electromagnetic damper for the vibration control of flexible structures and rotors. The study has been performed in the case of a single degree of freedom mechanical oscillator actuated by a couple of electromagnets. The self-sensing system is based on a Luenberger observer. Two sets of parameters have been used: nominal ones (based on simplifications on the actuator model) and identified ones. In the latter case, the parameters of the electromechanical model used in the observer are identified starting from the open-loop system response. The observed states are used to close a state-feedback loop with the objective of increasing the damping of the system. The results show that the damping performance are good in both cases, although much better in the second one. Furthermore, the good correlation between the closed-loop model response and the experimental results validates the modeling, the identification procedure, the control design, and its implementation. The paper concludes on a sensitivity analysis, in which the influence of the model parameters on the closed-loop response is shown. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

DMCMN / Matthew S. Allen in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 6 (Novembre 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 10 p. Titre : DMCMN : experimental/analytical evaluation of the effect of tip mass on atomic force microscope cantilever calibration Type de document : texte imprimé Auteurs : Matthew S. Allen, Auteur ; Hartono Sumali, Auteur ; Peter C. Penegor, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : tip  mass;  AFM  calibration;  atomic  force  microscope  cantilevers Résumé : Quantitative studies of material properties and interfaces using the atomic force microscope (AFM) have important applications in engineering, biotechnology, and chemistry. Contrary to what the name suggests, the AFM actually measures the displacement of a microscale probe, so one must determine the stiffness of the probe to find the force exerted on a sample. Numerous methods have been proposed for determining the spring constant of AFM cantilever probes, yet most neglect the mass of the probe tip. This work explores the effect of the tip mass on AFM calibration using the method of (1995, “Method for the Calibration of Atomic Force Microscope Cantilevers,” Rev. Sci. Instrum., 66, pp. 3789) and extends that method to account for a massive, rigid tip. One can use this modified method to estimate the spring constant of a cantilever from the measured natural frequency and Q-factor for any mode of the probe. This may be helpful when the fundamental mode is difficult to measure or to check for inaccuracies in the calibration obtained with the fundamental mode. The error analysis presented here shows that if the tip is not considered, then the error in the static stiffness is roughly of the same order as the ratio of the tip’s mass to the cantilever beam’s. The area density of the AFM probe is also misestimated if the tip mass is not accounted for, although the trends are different. The model presented here can be used to identify the mass of a probe tip from measurements of the natural frequencies of the probe. These concepts are applied to six low spring-constant, contact-mode AFM cantilevers, and the results suggest that some of the probes are well modeled by an Euler–Bernoulli beam with a constant cross section and a rigid tip, while others are not. One probe is examined in detail, using scanning electron microscopy to quantify the size of the tip and the thickness uniformity of the probe, and laser Doppler vibrometry is used to measure the first four mode shapes. The results suggest that this probe’s thickness is significantly nonuniform, so the models upon which dynamic calibration is based may not be appropriate for this probe. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...] [article] DMCMN : experimental/analytical evaluation of the effect of tip mass on atomic force microscope cantilever calibration [texte imprimé] / Matthew S. Allen, Auteur ; Hartono Sumali, Auteur ; Peter C. Penegor, Auteur . - 2010 . - 10 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 6 (Novembre 2009) . - 10 p. Mots-clés : tip  mass;  AFM  calibration;  atomic  force  microscope  cantilevers Résumé : Quantitative studies of material properties and interfaces using the atomic force microscope (AFM) have important applications in engineering, biotechnology, and chemistry. Contrary to what the name suggests, the AFM actually measures the displacement of a microscale probe, so one must determine the stiffness of the probe to find the force exerted on a sample. Numerous methods have been proposed for determining the spring constant of AFM cantilever probes, yet most neglect the mass of the probe tip. This work explores the effect of the tip mass on AFM calibration using the method of (1995, “Method for the Calibration of Atomic Force Microscope Cantilevers,” Rev. Sci. Instrum., 66, pp. 3789) and extends that method to account for a massive, rigid tip. One can use this modified method to estimate the spring constant of a cantilever from the measured natural frequency and Q-factor for any mode of the probe. This may be helpful when the fundamental mode is difficult to measure or to check for inaccuracies in the calibration obtained with the fundamental mode. The error analysis presented here shows that if the tip is not considered, then the error in the static stiffness is roughly of the same order as the ratio of the tip’s mass to the cantilever beam’s. The area density of the AFM probe is also misestimated if the tip mass is not accounted for, although the trends are different. The model presented here can be used to identify the mass of a probe tip from measurements of the natural frequencies of the probe. These concepts are applied to six low spring-constant, contact-mode AFM cantilevers, and the results suggest that some of the probes are well modeled by an Euler–Bernoulli beam with a constant cross section and a rigid tip, while others are not. One probe is examined in detail, using scanning electron microscopy to quantify the size of the tip and the thickness uniformity of the probe, and laser Doppler vibrometry is used to measure the first four mode shapes. The results suggest that this probe’s thickness is significantly nonuniform, so the models upon which dynamic calibration is based may not be appropriate for this probe. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26505&di [...]

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