Dépouillements

Analysis of the effect of strip buckling on stability of strip lateral motion with application to cold rolling of steel / T. Tarnopolskaya in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 07 p. Titre : Analysis of the effect of strip buckling on stability of strip lateral motion with application to cold rolling of steel Type de document : texte imprimé Auteurs : T. Tarnopolskaya, Auteur ; D. J. Gates, Auteur Année de publication : 2008 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : strip  buckling;  mathematical  model;  numerical  analysis Résumé : A sudden loss of lateral stability (strip track-off) is a serious operational problem in cold rolling of steel that often leads to catastrophic consequences such as mill crashes and roll damage. This paper studies the causes of instability in lateral motion of a metal strip in a single span between the uncoiler and the first stand of a cold rolling mill. A mathematical model of strip lateral dynamics that includes a rolling mill model and a simplified physically based model of strip buckling is formulated. The numerical analysis of the model reveals that in the presence of strip buckling, the lateral motion becomes unstable once a critical level of asymmetry in rolling conditions is exceeded. The critical level of asymmetry increases with the increase in the tension applied to the strip. Below this critical level of asymmetry, a sudden transition to unstable motion occurs if a critical lateral deviation is reached. This paper demonstrates that the buckling of the strip can be responsible for lateral instability. The results of this paper explain the sudden onset of instability observed in metal rolling and the stabilizing effect of the tension applied to the strip, known in rolling practice. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/mobile/article.aspx?article [...] [article] Analysis of the effect of strip buckling on stability of strip lateral motion with application to cold rolling of steel [texte imprimé] / T. Tarnopolskaya, Auteur ; D. J. Gates, Auteur . - 2008 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 07 p. Mots-clés : strip  buckling;  mathematical  model;  numerical  analysis Résumé : A sudden loss of lateral stability (strip track-off) is a serious operational problem in cold rolling of steel that often leads to catastrophic consequences such as mill crashes and roll damage. This paper studies the causes of instability in lateral motion of a metal strip in a single span between the uncoiler and the first stand of a cold rolling mill. A mathematical model of strip lateral dynamics that includes a rolling mill model and a simplified physically based model of strip buckling is formulated. The numerical analysis of the model reveals that in the presence of strip buckling, the lateral motion becomes unstable once a critical level of asymmetry in rolling conditions is exceeded. The critical level of asymmetry increases with the increase in the tension applied to the strip. Below this critical level of asymmetry, a sudden transition to unstable motion occurs if a critical lateral deviation is reached. This paper demonstrates that the buckling of the strip can be responsible for lateral instability. The results of this paper explain the sudden onset of instability observed in metal rolling and the stabilizing effect of the tension applied to the strip, known in rolling practice. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/mobile/article.aspx?article [...]

Control design for the active stabilization of rail wheelsets / T. X. Mei in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Titre : Control design for the active stabilization of rail wheelsets Type de document : texte imprimé Auteurs : T. X. Mei, Auteur ; H. Li, Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : railway  wheelset;  stabilization  control;  feedback Résumé : Through a detailed control assessment of a conventional railway wheelset, this paper addresses some of the key design issues in the development of active primary suspensions for the stabilization control of railway vehicles. It reveals the basic feedback requirements for achieving adequate stability and hence provides a useful insight of how active controllers may be structured. For the control design, a number of factors in addition to the stabilization are considered including the actuation requirements, creep forces at the wheel-rail contact, track following as well as robustness against parameter variations. Based on the outcome of the control analysis, the study proposes a design and optimization procedure for the development of active wheelset control. The design method is applied to a two-axle vehicle in a case study, which shows that the new design approach is advantageous when compared with other design methods previously studied. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Control design for the active stabilization of rail wheelsets [texte imprimé] / T. X. Mei, Auteur ; H. Li, Auteur . - 2008 . - 9 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Mots-clés : railway  wheelset;  stabilization  control;  feedback Résumé : Through a detailed control assessment of a conventional railway wheelset, this paper addresses some of the key design issues in the development of active primary suspensions for the stabilization control of railway vehicles. It reveals the basic feedback requirements for achieving adequate stability and hence provides a useful insight of how active controllers may be structured. For the control design, a number of factors in addition to the stabilization are considered including the actuation requirements, creep forces at the wheel-rail contact, track following as well as robustness against parameter variations. Based on the outcome of the control analysis, the study proposes a design and optimization procedure for the development of active wheelset control. The design method is applied to a two-axle vehicle in a case study, which shows that the new design approach is advantageous when compared with other design methods previously studied. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Disturbance rejection in the control of a maglev artificial heart / Luca Gentili in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 10 p. Titre : Disturbance rejection in the control of a maglev artificial heart Type de document : texte imprimé Auteurs : Luca Gentili, Auteur ; Paden, Brad, Auteur ; Lorenzo Marconi, Auteur Année de publication : 2008 Article en page(s) : 10 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : maglev  artificial  heart;  advanced  controller Résumé : This paper is devoted to the development of an advanced controller for a maglev artificial heart: in particular, a magnetically levitated left ventricular assist device is studied and the disturbances from the natural heart are taken into account. The main goal is to define a control action able to reject dc as well as periodical disturbances from the control input in steady state. This is accomplished by exploiting the intrinsic instability of the system. The paper presents a couple of approaches for solving the problem: an internal model based approach and a solution based on adaptive observers. The internal model based solution relies on the knowledge of the frequencies of the sinusoidal disturbances affecting the system: this hypothesis is not far from the reality of the maglev apparatus as the shape and frequency of the quasiperiodic disturbance can be known with the addition of sensors. The design methodology based on the use of adaptive observers does not require the perfect knowledge of the frequencies of sinusoidal disturbances as an adaptive mechanism is presented to estimate them. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Disturbance rejection in the control of a maglev artificial heart [texte imprimé] / Luca Gentili, Auteur ; Paden, Brad, Auteur ; Lorenzo Marconi, Auteur . - 2008 . - 10 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 10 p. Mots-clés : maglev  artificial  heart;  advanced  controller Résumé : This paper is devoted to the development of an advanced controller for a maglev artificial heart: in particular, a magnetically levitated left ventricular assist device is studied and the disturbances from the natural heart are taken into account. The main goal is to define a control action able to reject dc as well as periodical disturbances from the control input in steady state. This is accomplished by exploiting the intrinsic instability of the system. The paper presents a couple of approaches for solving the problem: an internal model based approach and a solution based on adaptive observers. The internal model based solution relies on the knowledge of the frequencies of the sinusoidal disturbances affecting the system: this hypothesis is not far from the reality of the maglev apparatus as the shape and frequency of the quasiperiodic disturbance can be known with the addition of sensors. The design methodology based on the use of adaptive observers does not require the perfect knowledge of the frequencies of sinusoidal disturbances as an adaptive mechanism is presented to estimate them. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Identification and control of chaos using fuzzy clustering and sliding mode control in unmodeled affine dynamical systems / Aria Alasty in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 8 p. Titre : Identification and control of chaos using fuzzy clustering and sliding mode control in unmodeled affine dynamical systems Type de document : texte imprimé Auteurs : Aria Alasty, Auteur ; Hassan Salarieh, Auteur Année de publication : 2008 Article en page(s) : 8 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : chaotic  system;  fuzzy  clustering  estimation;  sliding  mode  control Résumé : In this paper, a combination of fuzzy clustering estimation and sliding mode control is used to control a chaotic system, which its mathematical model is unknown. It is assumed that the chaotic system has an affine form. At first, the nonlinear noninput part of the chaotic system is estimated by a fuzzy model, without using any input noise signal. Without loss of generality, it is assumed that chaotic behavior is appeared in the absence of input signal. In this case, the recurrent property of chaotic behavior is used for estimating its model. After constructing the fuzzy model, which estimates the noninput part of the chaotic system, control and on-line identification of the input-related section are applied. In this step, the system model will be estimated in normal form, such that the dynamic equations can be used in sliding mode control. Finally, the proposed technique is applied to a Lur’e-like dynamic system and the Lorenz system as two illustrative examples of chaotic systems. The simulation results verify the effectiveness of this approach in controlling an unknown chaotic system. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Identification and control of chaos using fuzzy clustering and sliding mode control in unmodeled affine dynamical systems [texte imprimé] / Aria Alasty, Auteur ; Hassan Salarieh, Auteur . - 2008 . - 8 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 8 p. Mots-clés : chaotic  system;  fuzzy  clustering  estimation;  sliding  mode  control Résumé : In this paper, a combination of fuzzy clustering estimation and sliding mode control is used to control a chaotic system, which its mathematical model is unknown. It is assumed that the chaotic system has an affine form. At first, the nonlinear noninput part of the chaotic system is estimated by a fuzzy model, without using any input noise signal. Without loss of generality, it is assumed that chaotic behavior is appeared in the absence of input signal. In this case, the recurrent property of chaotic behavior is used for estimating its model. After constructing the fuzzy model, which estimates the noninput part of the chaotic system, control and on-line identification of the input-related section are applied. In this step, the system model will be estimated in normal form, such that the dynamic equations can be used in sliding mode control. Finally, the proposed technique is applied to a Lur’e-like dynamic system and the Lorenz system as two illustrative examples of chaotic systems. The simulation results verify the effectiveness of this approach in controlling an unknown chaotic system. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Dynamic image-based visual servo control using centroid and optic flow features / R. Mahony in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 12 p. Titre : Dynamic image-based visual servo control using centroid and optic flow features Type de document : texte imprimé Auteurs : R. Mahony, Auteur ; P. Corke, Auteur ; T. Hamel, Auteur Année de publication : 2008 Article en page(s) : 12 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : dynamic  systems;  image-based  visual  servo  control;  robotic  vehicles;  nonlinear  adaptive  control Résumé : This paper considers the question of designing a fully image-based visual servo control for a class of dynamic systems. The work is motivated by the ongoing development of image-based visual servo control of small aerial robotic vehicles. The kinematics and dynamics of a rigid-body dynamical system (such as a vehicle airframe) maneuvering over a flat target plane with observable features are expressed in terms of an un-normalized spherical centroid and an optic flow measurement. The image-plane dynamics with respect to force input are dependent on the height of the camera above the target plane. This dependence is compensated by introducing virtual height dynamics and adaptive estimation in the proposed control. A fully nonlinear adaptive control design is provided that ensures asymptotic stability of the closed-loop system for all feasible initial conditions. The choice of control gains is based on an analysis of the asymptotic dynamics of the system. Results from a realistic simulation are presented that demonstrate the performance of the closed-loop system. To the author’s knowledge, this paper documents the first time that an image-based visual servo control has been proposed for a dynamic system using vision measurement for both position and velocity. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Dynamic image-based visual servo control using centroid and optic flow features [texte imprimé] / R. Mahony, Auteur ; P. Corke, Auteur ; T. Hamel, Auteur . - 2008 . - 12 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 12 p. Mots-clés : dynamic  systems;  image-based  visual  servo  control;  robotic  vehicles;  nonlinear  adaptive  control Résumé : This paper considers the question of designing a fully image-based visual servo control for a class of dynamic systems. The work is motivated by the ongoing development of image-based visual servo control of small aerial robotic vehicles. The kinematics and dynamics of a rigid-body dynamical system (such as a vehicle airframe) maneuvering over a flat target plane with observable features are expressed in terms of an un-normalized spherical centroid and an optic flow measurement. The image-plane dynamics with respect to force input are dependent on the height of the camera above the target plane. This dependence is compensated by introducing virtual height dynamics and adaptive estimation in the proposed control. A fully nonlinear adaptive control design is provided that ensures asymptotic stability of the closed-loop system for all feasible initial conditions. The choice of control gains is based on an analysis of the asymptotic dynamics of the system. Results from a realistic simulation are presented that demonstrate the performance of the closed-loop system. To the author’s knowledge, this paper documents the first time that an image-based visual servo control has been proposed for a dynamic system using vision measurement for both position and velocity. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Nondiagonal MIMO QFT controller design for Darwin-type spacecraft with large flimsy appendages / Mario Garcia-Sanz in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 15 p. Titre : Nondiagonal MIMO QFT controller design for Darwin-type spacecraft with large flimsy appendages Type de document : texte imprimé Auteurs : Mario Garcia-Sanz, Auteur ; Samir Bennani, Auteur ; Irene Eguinoa, Auteur Année de publication : 2008 Article en page(s) : 15 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : robust  control  strategies;  Darwin-type  spacecraft;  flexible  appendages Résumé : This paper deals with the design of robust control strategies to govern the position and attitude of a Darwin-type spacecraft with large flexible appendages. The satellite is one of the flyers of a multiple spacecraft constellation for a future ESA mission. It presents a 6×6 high order multiple-input–multiple-output (MIMO) model with large uncertainty and loop interactions introduced by the flexible modes of the low-stiffness appendages. The scientific objectives of the satellite require very demanding control specifications for position and attitude accuracy, high disturbance rejection, loop-coupling attenuation, and low controller order. The paper demonstrates the feasibility of a sequential nondiagonal MIMO quantitative feedback theory (QFT) strategy controlling the Darwin spacecraft and compares the results with H-infinity and sequential diagonal MIMO QFT designs. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Nondiagonal MIMO QFT controller design for Darwin-type spacecraft with large flimsy appendages [texte imprimé] / Mario Garcia-Sanz, Auteur ; Samir Bennani, Auteur ; Irene Eguinoa, Auteur . - 2008 . - 15 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 15 p. Mots-clés : robust  control  strategies;  Darwin-type  spacecraft;  flexible  appendages Résumé : This paper deals with the design of robust control strategies to govern the position and attitude of a Darwin-type spacecraft with large flexible appendages. The satellite is one of the flyers of a multiple spacecraft constellation for a future ESA mission. It presents a 6×6 high order multiple-input–multiple-output (MIMO) model with large uncertainty and loop interactions introduced by the flexible modes of the low-stiffness appendages. The scientific objectives of the satellite require very demanding control specifications for position and attitude accuracy, high disturbance rejection, loop-coupling attenuation, and low controller order. The paper demonstrates the feasibility of a sequential nondiagonal MIMO quantitative feedback theory (QFT) strategy controlling the Darwin spacecraft and compares the results with H-infinity and sequential diagonal MIMO QFT designs. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Force control loop affected by bounded uncertainties and unbounded inputs for pneumatic actuator systems / Khayati, Karim in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Titre : Force control loop affected by bounded uncertainties and unbounded inputs for pneumatic actuator systems Type de document : texte imprimé Auteurs : Khayati, Karim, Auteur ; Bigras, Pascal, Auteur ; Dessaint, Louis-A., Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : closed-loop;  pneumatic  actuator;  analytical  nonlinear  structure;  linear  state-feedback  control Résumé : The purpose of this paper is to develop an accurate closed-loop acting force technique for a pneumatic actuator, as an essential stage in the implementation of positioning control strategy. Since an analytical nonlinear structure, which linearly depends on parameter uncertainties, generically characterizes pneumatic plants, a feedback linearization design is proposed to cancel most of the resulting nonlinearities. Then, we proposed a linear state-feedback control and an additive nonlinear action to robustly bound the force error dynamics, devices which are required to handle the further parametric uncertainties and exogenous unbounded disturbances that will arise on the deduced structure. The design of the linear control gains is performed within robust closed-loop pole clustering using a linear matrix inequality approach. Finally, various experimental results illustrate the validity of the approach. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Force control loop affected by bounded uncertainties and unbounded inputs for pneumatic actuator systems [texte imprimé] / Khayati, Karim, Auteur ; Bigras, Pascal, Auteur ; Dessaint, Louis-A., Auteur . - 2008 . - 9 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Mots-clés : closed-loop;  pneumatic  actuator;  analytical  nonlinear  structure;  linear  state-feedback  control Résumé : The purpose of this paper is to develop an accurate closed-loop acting force technique for a pneumatic actuator, as an essential stage in the implementation of positioning control strategy. Since an analytical nonlinear structure, which linearly depends on parameter uncertainties, generically characterizes pneumatic plants, a feedback linearization design is proposed to cancel most of the resulting nonlinearities. Then, we proposed a linear state-feedback control and an additive nonlinear action to robustly bound the force error dynamics, devices which are required to handle the further parametric uncertainties and exogenous unbounded disturbances that will arise on the deduced structure. The design of the linear control gains is performed within robust closed-loop pole clustering using a linear matrix inequality approach. Finally, various experimental results illustrate the validity of the approach. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Development of a vehicle stability control system using brake-by-wire actuators / Daegun Hong in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Titre : Development of a vehicle stability control system using brake-by-wire actuators Type de document : texte imprimé Auteurs : Daegun Hong, Auteur ; Inyong Hwang, Auteur ; Kunsoo, Huh, Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : wheel  slip  control  systems;  vehicle  stability  control  system;  braking  monitor;  target  slip Résumé : The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional braking control systems. In order to achieve the superior braking performance through the wheel slip control, real-time information such as tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance, stability enhancement, etc. In this paper, a vehicle stability control system is developed based on the braking monitor, wheel slip controller, and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force, and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw-moment controller and fuzzy logic. A hardware-in-the-loop simulator (HILS) is built including electrohydraulic brake hardware and vehicle dynamics software. The effectiveness of the proposed stability control system is demonstrated through the HILS experiment. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Development of a vehicle stability control system using brake-by-wire actuators [texte imprimé] / Daegun Hong, Auteur ; Inyong Hwang, Auteur ; Kunsoo, Huh, Auteur . - 2008 . - 9 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Mots-clés : wheel  slip  control  systems;  vehicle  stability  control  system;  braking  monitor;  target  slip Résumé : The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional braking control systems. In order to achieve the superior braking performance through the wheel slip control, real-time information such as tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance, stability enhancement, etc. In this paper, a vehicle stability control system is developed based on the braking monitor, wheel slip controller, and optimal target slip assignment algorithm. The braking monitor estimates the tire braking force, lateral tire force, and brake disk-pad friction coefficient utilizing the extended Kalman filter. The wheel slip controller is designed based on the sliding mode control method. The target slip assignment algorithm is proposed to maintain the vehicle stability based on the direct yaw-moment controller and fuzzy logic. A hardware-in-the-loop simulator (HILS) is built including electrohydraulic brake hardware and vehicle dynamics software. The effectiveness of the proposed stability control system is demonstrated through the HILS experiment. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Discrete Lagrange equations for thermofluid systems / Fahrenthold, Eric P. in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 7 p. Titre : Discrete Lagrange equations for thermofluid systems Type de document : texte imprimé Auteurs : Fahrenthold, Eric P., Auteur ; Charles R. Hean, Auteur Année de publication : 2008 Article en page(s) : 7 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : thermofluid  systems;  Lagrange  equation;  discrete  energy  method Résumé : A primary focus of the system dynamics literature is the development of structured modeling methods, suitable for application to a diverse array of engineering problems. An important obstacle in the development of unified modeling methods is the need to employ Eulerian reference frames in many thermofluid systems applications. An extension of Lagrange’s equations, to compressible thermofluid dynamics in Eulerian frames, offers a general modeling methodology for thermofluid systems compatible with discrete energy methods widely used for mechanical systems simulations. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Discrete Lagrange equations for thermofluid systems [texte imprimé] / Fahrenthold, Eric P., Auteur ; Charles R. Hean, Auteur . - 2008 . - 7 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 7 p. Mots-clés : thermofluid  systems;  Lagrange  equation;  discrete  energy  method Résumé : A primary focus of the system dynamics literature is the development of structured modeling methods, suitable for application to a diverse array of engineering problems. An important obstacle in the development of unified modeling methods is the need to employ Eulerian reference frames in many thermofluid systems applications. An extension of Lagrange’s equations, to compressible thermofluid dynamics in Eulerian frames, offers a general modeling methodology for thermofluid systems compatible with discrete energy methods widely used for mechanical systems simulations. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

A quadratic numerical scheme for fractional optimal control problems / Om P. Agrawal in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 6 p. Titre : A quadratic numerical scheme for fractional optimal control problems Type de document : texte imprimé Auteurs : Om P. Agrawal, Auteur Année de publication : 2008 Article en page(s) : 6 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : fractional  optimal  control  problems;  quadratic  numerical  scheme;  Lagrange  multiplier Résumé : This paper presents a quadratic numerical scheme for a class of fractional optimal control problems (FOCPs). The fractional derivative is described in the Caputo sense. The performance index of a FOCP is considered as a function of both the state and the control variables, and the dynamic constraints are expressed by a set of fractional differential equations. The calculus of variations, the Lagrange multiplier, and the formula for fractional integration by parts are used to obtain Euler–Lagrange equations for the FOCP. The formulation presented and the resulting equations are very similar to those that appear in the classical optimal control theory. Thus, the present formulation essentially extends the classical control theory to fractional dynamic systems. The formulation is used to derive the control equations for a quadratic linear fractional control problem. For a linear system, this method results into a set of linear simultaneous equations, which can be solved using a direct or an iterative scheme. Numerical results for a FOCP are presented to demonstrate the feasibility of the method. It is shown that the solutions converge as the number of grid points increases, and the solutions approach to classical solutions as the order of the fractional derivatives approach to 1. The formulation presented is simple and can be extended to other FOCPs. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] A quadratic numerical scheme for fractional optimal control problems [texte imprimé] / Om P. Agrawal, Auteur . - 2008 . - 6 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 6 p. Mots-clés : fractional  optimal  control  problems;  quadratic  numerical  scheme;  Lagrange  multiplier Résumé : This paper presents a quadratic numerical scheme for a class of fractional optimal control problems (FOCPs). The fractional derivative is described in the Caputo sense. The performance index of a FOCP is considered as a function of both the state and the control variables, and the dynamic constraints are expressed by a set of fractional differential equations. The calculus of variations, the Lagrange multiplier, and the formula for fractional integration by parts are used to obtain Euler–Lagrange equations for the FOCP. The formulation presented and the resulting equations are very similar to those that appear in the classical optimal control theory. Thus, the present formulation essentially extends the classical control theory to fractional dynamic systems. The formulation is used to derive the control equations for a quadratic linear fractional control problem. For a linear system, this method results into a set of linear simultaneous equations, which can be solved using a direct or an iterative scheme. Numerical results for a FOCP are presented to demonstrate the feasibility of the method. It is shown that the solutions converge as the number of grid points increases, and the solutions approach to classical solutions as the order of the fractional derivatives approach to 1. The formulation presented is simple and can be extended to other FOCPs. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Pressure, flow, force, and torque between the barrel and port plate in an axial piston pump / J. M. Bergada in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 16 p. Titre : Pressure, flow, force, and torque between the barrel and port plate in an axial piston pump Type de document : texte imprimé Auteurs : J. M. Bergada, Auteur ; J. Watton, Auteur ; Kumar, S., Auteur Année de publication : 2008 Article en page(s) : 16 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : barrel;  axial  piston  pump;  pressure  distribution;  leakage;  force;  torque Résumé : This paper analyzes the pressure distribution, leakage, force, and torque between the barrel and the port plate of an axial piston pump. A detailed set of new equations is developed, which takes into account important parameters such as tilt, clearance and rotational speed, and timing groove. The pressure distribution is derived for different operating conditions, together with a complementary numerical analysis of the original differential equations, specifically written for this application and used to validate the theoretical solutions. An excellent agreement between the two approaches is shown, allowing an explicit analytical insight into barrel/port plate operating characteristics, including consideration of cavitation. The overall mean force and torques over the barrel are evaluated and show that the torque over the XX axis is much smaller than the torque over the YY axis, as deduced from other nonexplicit simulation approaches. A detailed dynamic analysis is then studied, and it is shown that the torque fluctuation over the YY axis is typically 8% of the torque total magnitude. Of particular novelty is the prediction of a double peak in each torque fluctuation resulting from the more exact modeling of the piston/port plate/timing groove pressure distribution characteristic during motion. A comparison between the temporal torque fluctuation pattern and another work shows a good qualitative agreement. Experimental and analytical results for the present study demonstrate that barrel dynamics do contain a component primarily directed by the torque dynamics. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Pressure, flow, force, and torque between the barrel and port plate in an axial piston pump [texte imprimé] / J. M. Bergada, Auteur ; J. Watton, Auteur ; Kumar, S., Auteur . - 2008 . - 16 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 16 p. Mots-clés : barrel;  axial  piston  pump;  pressure  distribution;  leakage;  force;  torque Résumé : This paper analyzes the pressure distribution, leakage, force, and torque between the barrel and the port plate of an axial piston pump. A detailed set of new equations is developed, which takes into account important parameters such as tilt, clearance and rotational speed, and timing groove. The pressure distribution is derived for different operating conditions, together with a complementary numerical analysis of the original differential equations, specifically written for this application and used to validate the theoretical solutions. An excellent agreement between the two approaches is shown, allowing an explicit analytical insight into barrel/port plate operating characteristics, including consideration of cavitation. The overall mean force and torques over the barrel are evaluated and show that the torque over the XX axis is much smaller than the torque over the YY axis, as deduced from other nonexplicit simulation approaches. A detailed dynamic analysis is then studied, and it is shown that the torque fluctuation over the YY axis is typically 8% of the torque total magnitude. Of particular novelty is the prediction of a double peak in each torque fluctuation resulting from the more exact modeling of the piston/port plate/timing groove pressure distribution characteristic during motion. A comparison between the temporal torque fluctuation pattern and another work shows a good qualitative agreement. Experimental and analytical results for the present study demonstrate that barrel dynamics do contain a component primarily directed by the torque dynamics. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Model order reduction of 1D diffusion systems via residue grouping / Kandler A. Smith in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 8 p. Titre : Model order reduction of 1D diffusion systems via residue grouping Type de document : texte imprimé Auteurs : Kandler A. Smith, Auteur ; Christopher D. Rahn, Auteur ; Chao-Yang Wang, Auteur Année de publication : 2008 Article en page(s) : 8 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : model  order  reduction  method;  1D  diffusion  systems;  negative  real  eigenvalues Résumé : A model order reduction method is developed and applied to 1D diffusion systems with negative real eigenvalues. Spatially distributed residues are found either analytically (from a transcendental transfer function) or numerically (from a finite element or finite difference state space model), and residues with similar eigenvalues are grouped together to reduce the model order. Two examples are presented from a model of a lithium ion electrochemical cell. Reduced order grouped models are compared to full order models and models of the same order in which optimal eigenvalues and residues are found numerically. The grouped models give near-optimal performance with roughly 1∕20 the computation time of the full order models and require 1000–5000 times less CPU time for numerical identification compared to the optimization procedure. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Model order reduction of 1D diffusion systems via residue grouping [texte imprimé] / Kandler A. Smith, Auteur ; Christopher D. Rahn, Auteur ; Chao-Yang Wang, Auteur . - 2008 . - 8 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 8 p. Mots-clés : model  order  reduction  method;  1D  diffusion  systems;  negative  real  eigenvalues Résumé : A model order reduction method is developed and applied to 1D diffusion systems with negative real eigenvalues. Spatially distributed residues are found either analytically (from a transcendental transfer function) or numerically (from a finite element or finite difference state space model), and residues with similar eigenvalues are grouped together to reduce the model order. Two examples are presented from a model of a lithium ion electrochemical cell. Reduced order grouped models are compared to full order models and models of the same order in which optimal eigenvalues and residues are found numerically. The grouped models give near-optimal performance with roughly 1∕20 the computation time of the full order models and require 1000–5000 times less CPU time for numerical identification compared to the optimization procedure. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Stability of controlled mechanical systems with ideal coulomb friction / Soo Jeon in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Titre : Stability of controlled mechanical systems with ideal coulomb friction Type de document : texte imprimé Auteurs : Soo Jeon, Auteur ; Tomizuka, Masayoshi, Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : stability;  friction;  coulombs;  equilibrium  (physics);  cycles;  closed  loop  systems Résumé : When a mechanical system with Coulomb friction is under feedback control, the closed-loop system may asymptotically converge to a point in the equilibrium set or generate nonlinear oscillations such as limit cycles depending on the control algorithm. Thus, it is important to know how to guarantee the stability in the presence of Coulomb friction. This paper presents the stability analysis of controlled mechanical systems with multiple ideal Coulomb friction sources. Common properties of controlled mechanical systems with multiple ideal Coulomb friction sources have been explored and generalized into the state space formulation leading to a class of ideal relay feedback systems. Various stability criteria are considered and a new sufficient condition for the pointwise global stability is suggested. Simulation results for a single mass system and experimental results for a single link flexible joint mechanism are presented to confirm the analysis and to illustrate various aspects of stability conditions for controlled mechanical systems with ideal Coulomb friction. The results given in this paper can be useful for the design of mechanical systems free from the limit cycle. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Stability of controlled mechanical systems with ideal coulomb friction [texte imprimé] / Soo Jeon, Auteur ; Tomizuka, Masayoshi, Auteur . - 2008 . - 9 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Mots-clés : stability;  friction;  coulombs;  equilibrium  (physics);  cycles;  closed  loop  systems Résumé : When a mechanical system with Coulomb friction is under feedback control, the closed-loop system may asymptotically converge to a point in the equilibrium set or generate nonlinear oscillations such as limit cycles depending on the control algorithm. Thus, it is important to know how to guarantee the stability in the presence of Coulomb friction. This paper presents the stability analysis of controlled mechanical systems with multiple ideal Coulomb friction sources. Common properties of controlled mechanical systems with multiple ideal Coulomb friction sources have been explored and generalized into the state space formulation leading to a class of ideal relay feedback systems. Various stability criteria are considered and a new sufficient condition for the pointwise global stability is suggested. Simulation results for a single mass system and experimental results for a single link flexible joint mechanism are presented to confirm the analysis and to illustrate various aspects of stability conditions for controlled mechanical systems with ideal Coulomb friction. The results given in this paper can be useful for the design of mechanical systems free from the limit cycle. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Position control using acceleration-based identification and feedback with unknown measurement bias / Jaganath Chandrasekar in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Titre : Position control using acceleration-based identification and feedback with unknown measurement bias Type de document : texte imprimé Auteurs : Jaganath Chandrasekar, Auteur ; Dennis S. Bernstein, Auteur Année de publication : 2008 Article en page(s) : 9 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : asymptotically  stable  linear  systems;  position-command  problem;  linear  quadratic  Gaussian  techniques Résumé : A position-command-following problem for asymptotically stable linear systems is considered. To account for modeling limitations, we assume that a model is not available. Instead, acceleration data are used to construct a compliance (position-output) model, which is subsequently used to design a position servo loop. Furthermore, we assume that the acceleration measurements obtained from inertial sensors are biased. A subspace identification algorithm is used to identify the inertance (acceleration-output) model, and the biased acceleration measurements are used by the position-command-following controller, which is constructed using linear quadratic Gaussian (LQG) techniques. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Position control using acceleration-based identification and feedback with unknown measurement bias [texte imprimé] / Jaganath Chandrasekar, Auteur ; Dennis S. Bernstein, Auteur . - 2008 . - 9 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 9 p. Mots-clés : asymptotically  stable  linear  systems;  position-command  problem;  linear  quadratic  Gaussian  techniques Résumé : A position-command-following problem for asymptotically stable linear systems is considered. To account for modeling limitations, we assume that a model is not available. Instead, acceleration data are used to construct a compliance (position-output) model, which is subsequently used to design a position servo loop. Furthermore, we assume that the acceleration measurements obtained from inertial sensors are biased. A subspace identification algorithm is used to identify the inertance (acceleration-output) model, and the biased acceleration measurements are used by the position-command-following controller, which is constructed using linear quadratic Gaussian (LQG) techniques. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

Tracking control of hydraulic actuators using a LuGre friction model compensation / Hairong Zeng in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 7 p. Titre : Tracking control of hydraulic actuators using a LuGre friction model compensation Type de document : texte imprimé Auteurs : Hairong Zeng, Auteur ; Sepehri, Nariman, Auteur Année de publication : 2008 Article en page(s) : 7 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : hydraulic  actuators;  robotic  systems;  tracking  control Résumé : This paper addresses the tracking control of hydraulic actuators commonly used in many hydraulically actuated robotic systems. Dynamic model of the entire actuator incorporating highly nonlinear hydraulic functions and the LuGre dynamic friction model is used to arrive at a suitable controller. The controller is augmented with adaptation laws to compensate for parametric uncertainties in the actuator dynamics, hydraulic functions as well as friction with nonuniform force variations. Furthermore, an adaptive observer is used in the controller to avoid the use of acceleration measurement. Therefore, only measurements of displacement, velocity, and hydraulic line pressures are required for the implementation of the proposed controller. Stability and convergence of the control system are theoretically studied. Experimental results are presented verifying the effectiveness of the developed controller. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Tracking control of hydraulic actuators using a LuGre friction model compensation [texte imprimé] / Hairong Zeng, Auteur ; Sepehri, Nariman, Auteur . - 2008 . - 7 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 7 p. Mots-clés : hydraulic  actuators;  robotic  systems;  tracking  control Résumé : This paper addresses the tracking control of hydraulic actuators commonly used in many hydraulically actuated robotic systems. Dynamic model of the entire actuator incorporating highly nonlinear hydraulic functions and the LuGre dynamic friction model is used to arrive at a suitable controller. The controller is augmented with adaptation laws to compensate for parametric uncertainties in the actuator dynamics, hydraulic functions as well as friction with nonuniform force variations. Furthermore, an adaptive observer is used in the controller to avoid the use of acceleration measurement. Therefore, only measurements of displacement, velocity, and hydraulic line pressures are required for the implementation of the proposed controller. Stability and convergence of the control system are theoretically studied. Experimental results are presented verifying the effectiveness of the developed controller. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]

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