Dépouillements

Two-level nonlinear model predictive control for lean NOx trap regenerations / Ming-Feng Hsieh in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 13 p. Titre : Two-level nonlinear model predictive control for lean NOx trap regenerations Type de document : texte imprimé Auteurs : Ming-Feng Hsieh, Auteur ; Wang, Junmin, Auteur ; Canova, Marcello, Auteur Année de publication : 2010 Article en page(s) : 13 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Diesel  engines  Nitrogen  compounds  Nonlinear  control  systems  Predictive  control Index. décimale : 629.8 Résumé : This paper describes a two-level nonlinear model predictive control (NMPC) scheme for diesel engine lean NOx trap (LNT) regeneration control. Based on the physical insights into the LNT operational characteristics, a two-level NMPC architecture with the higher-level for the regeneration timing control and the lower-level for the regeneration air to fuel ratio profile control is proposed. A physically based and experimentally validated nonlinear LNT dynamic model is employed to construct the NMPC control algorithms. The control objective is to minimize the fuel penalty induced by LNT regenerations while keeping the tailpipe NOx emissions below the regulations. Based on the physical insights into the LNT system dynamics, different choices of cost function were examined in terms of the impacts on fuel penalty and tailpipe NOx slip amount. The designed control system was evaluated on an experimentally validated vehicle simulator, cX-Emissions, with a 1.9 l diesel engine model through the FTP75 driving cycle. Compared with a conventional LNT control strategy, 31.9% of regeneration fuel penalty reduction was observed during a single regeneration. For the entire cold-start FTP75 test cycle, a 28.1% of tailpipe NOx reduction and 40.9% of fuel penalty reduction were achieved. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Two-level nonlinear model predictive control for lean NOx trap regenerations [texte imprimé] / Ming-Feng Hsieh, Auteur ; Wang, Junmin, Auteur ; Canova, Marcello, Auteur . - 2010 . - 13 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 13 p. Mots-clés : Diesel  engines  Nitrogen  compounds  Nonlinear  control  systems  Predictive  control Index. décimale : 629.8 Résumé : This paper describes a two-level nonlinear model predictive control (NMPC) scheme for diesel engine lean NOx trap (LNT) regeneration control. Based on the physical insights into the LNT operational characteristics, a two-level NMPC architecture with the higher-level for the regeneration timing control and the lower-level for the regeneration air to fuel ratio profile control is proposed. A physically based and experimentally validated nonlinear LNT dynamic model is employed to construct the NMPC control algorithms. The control objective is to minimize the fuel penalty induced by LNT regenerations while keeping the tailpipe NOx emissions below the regulations. Based on the physical insights into the LNT system dynamics, different choices of cost function were examined in terms of the impacts on fuel penalty and tailpipe NOx slip amount. The designed control system was evaluated on an experimentally validated vehicle simulator, cX-Emissions, with a 1.9 l diesel engine model through the FTP75 driving cycle. Compared with a conventional LNT control strategy, 31.9% of regeneration fuel penalty reduction was observed during a single regeneration. For the entire cold-start FTP75 test cycle, a 28.1% of tailpipe NOx reduction and 40.9% of fuel penalty reduction were achieved. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Enabling automation of friction stir welding / William R. Longhurst in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Titre : Enabling automation of friction stir welding : the modulation of weld seam input energy by traverse speed force control Type de document : texte imprimé Auteurs : William R. Longhurst, Auteur ; Alvin M. Strauss, Auteur ; George E. Cook, Auteur Année de publication : 2010 Article en page(s) : 11 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Automation  Force  control  Forging  Friction  welding  Machinery  Milling  machines  Three-term  control  Transfer  functions  Welding Index. décimale : 629.8 Résumé : Friction stir welding (FSW) joins materials by plunging a rotating tool into the work piece. The tool consists of a shoulder and a pin that plastically deforms the parent materials and then forges them together under the applied pressure. To create the pressure needed for forging, a rather large axial force must be maintained on the tool. Maintaining this axial force is challenging for robots due to their limited load capacity and compliant nature. To address this problem, force control has been used, and historically, the force has been controlled by adjusting the plunge depth of the tool into the work piece. This paper develops the use of tool traverse speed as the controlling variable instead of plunge depth. To perform this investigation, a FSW force controller was designed and implemented on a retrofitted Milwaukee Model K milling machine. The closed loop proportional, integral plus derivative (PID) control architecture was tuned using the Ziegler–Nichols method. Results show that the control of axial force via traverse speed is feasible and predictable. The resulting system is more robust and stable when compared with a force controller that uses plunge depth as the controlling variable. A standard deviation of 41.5 N was obtained. This variation is much less when compared with a standard deviation of 129.4 N obtained when using plunge depth. Using various combinations of PID control, the system's response to step inputs was analyzed. From this analysis, a feed forward transfer function was modeled that describes the machinery and welding environment. From these results, a technique is presented regarding weld seam input energy modulation as a by product of force control via traverse speed. A relative indication of thermal energy in the welding environment is obtained with the feedback of axial force. It is hypothesized that, while under force control, the controller modulates weld seam input energy according to the control signal. The result is constant thermomechanical conditions in the welding environment. It is concluded that the key enablers for force control are the unidirectional behavior and load dynamics of the traverse motor. Larger bandwidths and more stable weld conditions emerge when using traverse speed instead of plunge depth to control the force. Force control of FSW via traverse speed has importance in creating efficient automatic manufacturing operations. The intelligence of the controller naturally selects the most efficient traverse speed. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Enabling automation of friction stir welding : the modulation of weld seam input energy by traverse speed force control [texte imprimé] / William R. Longhurst, Auteur ; Alvin M. Strauss, Auteur ; George E. Cook, Auteur . - 2010 . - 11 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Mots-clés : Automation  Force  control  Forging  Friction  welding  Machinery  Milling  machines  Three-term  control  Transfer  functions  Welding Index. décimale : 629.8 Résumé : Friction stir welding (FSW) joins materials by plunging a rotating tool into the work piece. The tool consists of a shoulder and a pin that plastically deforms the parent materials and then forges them together under the applied pressure. To create the pressure needed for forging, a rather large axial force must be maintained on the tool. Maintaining this axial force is challenging for robots due to their limited load capacity and compliant nature. To address this problem, force control has been used, and historically, the force has been controlled by adjusting the plunge depth of the tool into the work piece. This paper develops the use of tool traverse speed as the controlling variable instead of plunge depth. To perform this investigation, a FSW force controller was designed and implemented on a retrofitted Milwaukee Model K milling machine. The closed loop proportional, integral plus derivative (PID) control architecture was tuned using the Ziegler–Nichols method. Results show that the control of axial force via traverse speed is feasible and predictable. The resulting system is more robust and stable when compared with a force controller that uses plunge depth as the controlling variable. A standard deviation of 41.5 N was obtained. This variation is much less when compared with a standard deviation of 129.4 N obtained when using plunge depth. Using various combinations of PID control, the system's response to step inputs was analyzed. From this analysis, a feed forward transfer function was modeled that describes the machinery and welding environment. From these results, a technique is presented regarding weld seam input energy modulation as a by product of force control via traverse speed. A relative indication of thermal energy in the welding environment is obtained with the feedback of axial force. It is hypothesized that, while under force control, the controller modulates weld seam input energy according to the control signal. The result is constant thermomechanical conditions in the welding environment. It is concluded that the key enablers for force control are the unidirectional behavior and load dynamics of the traverse motor. Larger bandwidths and more stable weld conditions emerge when using traverse speed instead of plunge depth to control the force. Force control of FSW via traverse speed has importance in creating efficient automatic manufacturing operations. The intelligence of the controller naturally selects the most efficient traverse speed. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Optimal sliding mode dual-stage actuator control in computer disk drives / Seung-Hi Lee in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 09 p. Titre : Optimal sliding mode dual-stage actuator control in computer disk drives Type de document : texte imprimé Auteurs : Seung-Hi Lee, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Control  system  synthesis  Disc  drives  Discrete  time  systems  Microactuators  Optimal  control  Variable  structure  systems Index. décimale : 629.8 Résumé : This paper presents a discrete-time design of a dual-stage actuator control system with sliding mode for computer disk drives. A state estimator based discrete-time boundary layer sliding mode control scheme is developed for a dual-stage actuator, which consists of a voice coil motor and a microactuator. Considering dominant microactuator flexible mode dynamics and the interaction between the two actuators, an optimal sliding hyperplane is designed to maximize their cooperation so as to attain desired responses. An application example demonstrates the utility of the proposed sliding mode dual-stage actuator control scheme for track-seek in the microactuator range, settle, and track-follow. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Optimal sliding mode dual-stage actuator control in computer disk drives [texte imprimé] / Seung-Hi Lee, Auteur . - 2010 . - 09 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 09 p. Mots-clés : Control  system  synthesis  Disc  drives  Discrete  time  systems  Microactuators  Optimal  control  Variable  structure  systems Index. décimale : 629.8 Résumé : This paper presents a discrete-time design of a dual-stage actuator control system with sliding mode for computer disk drives. A state estimator based discrete-time boundary layer sliding mode control scheme is developed for a dual-stage actuator, which consists of a voice coil motor and a microactuator. Considering dominant microactuator flexible mode dynamics and the interaction between the two actuators, an optimal sliding hyperplane is designed to maximize their cooperation so as to attain desired responses. An application example demonstrates the utility of the proposed sliding mode dual-stage actuator control scheme for track-seek in the microactuator range, settle, and track-follow. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Multi-input multi-output (MIMO) modeling and control for stamping / Yongseob Lim in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 12 p. Titre : Multi-input multi-output (MIMO) modeling and control for stamping Type de document : texte imprimé Auteurs : Yongseob Lim, Auteur ; Ravinder Venugopal, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : Systèmes dynamique Langues : Anglais (eng) Mots-clés : Control  system  synthesis  Die  casting  Force  control  Metal  stamping  MIMO  systems  Parameter  estimation  Process  control  Sheet  metal  processing Index. décimale : 629.8 Résumé : The binder force in sheet metal forming controls the material flow into the die cavity. Maintaining precise material flow characteristics is crucial for producing a high-quality stamped part. Process control can be used to adjust the binder force based on tracking of a reference punch force trajectory to improve part quality and consistency. The purpose of this paper is to present a systematic approach to the design and implementation of a suitable multi-input multi-output (MIMO) process controller. An appropriate process model structure for the purpose of controller design for the sheet metal forming process is presented and the parameter estimation for this model is accomplished using system identification methods. This paper is based on original experiments performed with a new variable blank holder force (or variable binder force) system that includes 12 hydraulic actuators to control the binder force. Experimental results from a complex-geometry part show that the MIMO process controller designed through simulation is effective. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Multi-input multi-output (MIMO) modeling and control for stamping [texte imprimé] / Yongseob Lim, Auteur ; Ravinder Venugopal, Auteur . - 2010 . - 12 p. Systèmes dynamique Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 12 p. Mots-clés : Control  system  synthesis  Die  casting  Force  control  Metal  stamping  MIMO  systems  Parameter  estimation  Process  control  Sheet  metal  processing Index. décimale : 629.8 Résumé : The binder force in sheet metal forming controls the material flow into the die cavity. Maintaining precise material flow characteristics is crucial for producing a high-quality stamped part. Process control can be used to adjust the binder force based on tracking of a reference punch force trajectory to improve part quality and consistency. The purpose of this paper is to present a systematic approach to the design and implementation of a suitable multi-input multi-output (MIMO) process controller. An appropriate process model structure for the purpose of controller design for the sheet metal forming process is presented and the parameter estimation for this model is accomplished using system identification methods. This paper is based on original experiments performed with a new variable blank holder force (or variable binder force) system that includes 12 hydraulic actuators to control the binder force. Experimental results from a complex-geometry part show that the MIMO process controller designed through simulation is effective. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

UAS mission path planning system (MPPS) using hybrid-game coupled to multi-objective optimizer / DongSeop Lee in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Titre : UAS mission path planning system (MPPS) using hybrid-game coupled to multi-objective optimizer Type de document : texte imprimé Auteurs : DongSeop Lee, Auteur ; Jacques Periaux, Auteur ; Luis Felipe Gonzalez, Auteur Année de publication : 2010 Article en page(s) : 11 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Aircraft  control  Game  theory  Genetic  algorithms  Path  planning  Remotely  operated  vehicles  Splines  (mathematics) Index. décimale : 629.8 Résumé : This paper presents the application of advanced optimization techniques to unmanned aerial system mission path planning system (MPPS) using multi-objective evolutionary algorithms (MOEAs). Two types of multi-objective optimizers are compared; the MOEA nondominated sorting genetic algorithm II and a hybrid-game strategy are implemented to produce a set of optimal collision-free trajectories in a three-dimensional environment. The resulting trajectories on a three-dimensional terrain are collision-free and are represented by using Bézier spline curves from start position to target and then target to start position or different positions with altitude constraints. The efficiency of the two optimization methods is compared in terms of computational cost and design quality. Numerical results show the benefits of adding a hybrid-game strategy to a MOEA and for a MPPS. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] UAS mission path planning system (MPPS) using hybrid-game coupled to multi-objective optimizer [texte imprimé] / DongSeop Lee, Auteur ; Jacques Periaux, Auteur ; Luis Felipe Gonzalez, Auteur . - 2010 . - 11 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Mots-clés : Aircraft  control  Game  theory  Genetic  algorithms  Path  planning  Remotely  operated  vehicles  Splines  (mathematics) Index. décimale : 629.8 Résumé : This paper presents the application of advanced optimization techniques to unmanned aerial system mission path planning system (MPPS) using multi-objective evolutionary algorithms (MOEAs). Two types of multi-objective optimizers are compared; the MOEA nondominated sorting genetic algorithm II and a hybrid-game strategy are implemented to produce a set of optimal collision-free trajectories in a three-dimensional environment. The resulting trajectories on a three-dimensional terrain are collision-free and are represented by using Bézier spline curves from start position to target and then target to start position or different positions with altitude constraints. The efficiency of the two optimization methods is compared in terms of computational cost and design quality. Numerical results show the benefits of adding a hybrid-game strategy to a MOEA and for a MPPS. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Dynamic optimization of reactionless four-bar linkages / Qimi Jiang in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Titre : Dynamic optimization of reactionless four-bar linkages Type de document : texte imprimé Auteurs : Qimi Jiang, Auteur ; Clément M. Gosselin, Auteur Année de publication : 2010 Article en page(s) : 11 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Couplings  Manipulator  dynamics  Optimisation  Torque Index. décimale : 629.8 Résumé : Reactionless mechanisms have many important applications because of their zero reaction forces and moments at the base. However, in most cases, these mechanisms consume more energy than their unbalanced counterparts. This paper focuses on analyzing the relationship between the needed input torque and the dynamic parameters of reactionless four-bar linkages. The objective is to minimize the needed input torque by optimizing the relevant dynamic parameters. The dynamic analysis shows that the needed input torque mainly depends on the mass of the link, which needs to be balanced. The results obtained can be applied to the design optimization and dynamic control of the devices such as parallel manipulators composed of reactionless four-bar linkages. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Dynamic optimization of reactionless four-bar linkages [texte imprimé] / Qimi Jiang, Auteur ; Clément M. Gosselin, Auteur . - 2010 . - 11 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 11 p. Mots-clés : Couplings  Manipulator  dynamics  Optimisation  Torque Index. décimale : 629.8 Résumé : Reactionless mechanisms have many important applications because of their zero reaction forces and moments at the base. However, in most cases, these mechanisms consume more energy than their unbalanced counterparts. This paper focuses on analyzing the relationship between the needed input torque and the dynamic parameters of reactionless four-bar linkages. The objective is to minimize the needed input torque by optimizing the relevant dynamic parameters. The dynamic analysis shows that the needed input torque mainly depends on the mass of the link, which needs to be balanced. The results obtained can be applied to the design optimization and dynamic control of the devices such as parallel manipulators composed of reactionless four-bar linkages. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

H[infinity] closed-loop control for uncertain discrete input-shaped systems / Stergiopoulos, John in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 08 p. Titre : H[infinity] closed-loop control for uncertain discrete input-shaped systems Type de document : texte imprimé Auteurs : Stergiopoulos, John, Auteur ; Tzes, Anthony, Auteur Année de publication : 2010 Article en page(s) : 08 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Closed  loop  systems  Control  system  synthesis  Discrete  systems  Robust  control  Uncertain  systems Index. décimale : 629.8 Résumé : The article addresses the problem of stabilization for uncertain discrete input-shaped systems. The uncertainty affects the autoregressive portion of the transfer function of the system. A discrete input shaper compensator is designed in order to reduce the oscillations of the plant's response. The input-shaped system's dynamics are appropriately reformulated for robust controller synthesis, and a robust H[infinity]-controller is used in an outer-loop, in order to guarantee stability of the uncertain input-shaped plant. Simulation results confirm the efficacy of the proposed combined scheme in comparison with open-loop input shaping and closed-loop linear quadratic control. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] H[infinity] closed-loop control for uncertain discrete input-shaped systems [texte imprimé] / Stergiopoulos, John, Auteur ; Tzes, Anthony, Auteur . - 2010 . - 08 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 08 p. Mots-clés : Closed  loop  systems  Control  system  synthesis  Discrete  systems  Robust  control  Uncertain  systems Index. décimale : 629.8 Résumé : The article addresses the problem of stabilization for uncertain discrete input-shaped systems. The uncertainty affects the autoregressive portion of the transfer function of the system. A discrete input shaper compensator is designed in order to reduce the oscillations of the plant's response. The input-shaped system's dynamics are appropriately reformulated for robust controller synthesis, and a robust H[infinity]-controller is used in an outer-loop, in order to guarantee stability of the uncertain input-shaped plant. Simulation results confirm the efficacy of the proposed combined scheme in comparison with open-loop input shaping and closed-loop linear quadratic control. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Stochastic recruitment control of large ensemble systems with limited feedback / Lael U. Odhner in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 09 p. Titre : Stochastic recruitment control of large ensemble systems with limited feedback Type de document : texte imprimé Auteurs : Lael U. Odhner, Auteur ; Harry Asada, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Actuators  Biocontrol  Biomechanics  Control  system  synthesis  Feedback  Markov  processes  Prosthetics Index. décimale : 629.8 Résumé : A new approach to controlling the ensemble behavior of many identical agents is presented in this paper, inspired by motor recruitment in skeletal muscles. A group of finite state agents responds randomly to broadcast commands, each producing a state-dependent output that is measured in aggregate. Despite the lack of feedback signal and initial state information, this control architecture allows a single central controller to direct the aggregate output of the ensemble toward a desired value. First, the system is modeled as an ensemble of statistically independent, identically distributed, binary-state Markov processes with state transition probabilities designated by a central controller. Second, steady-state behavior, convergence rate, and variance of the aggregate output, i.e., the total number of recruited agents, are analyzed, and design trade-offs in terms of accuracy, convergence speed, and the number of spurious transitions are made. Third, a limited feedback signal, only detecting if the output has reached a goal, is added to the system, and the recruitment controller is designed as a stochastic shortest path problem. Optimal convergence rate and associated transition probabilities are obtained. Finally, the theoretical results are verified and demonstrated with both numerical simulation and control of an artificial muscle actuator made up of 60 binary shape memory alloy motor units. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Stochastic recruitment control of large ensemble systems with limited feedback [texte imprimé] / Lael U. Odhner, Auteur ; Harry Asada, Auteur . - 2010 . - 09 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 09 p. Mots-clés : Actuators  Biocontrol  Biomechanics  Control  system  synthesis  Feedback  Markov  processes  Prosthetics Index. décimale : 629.8 Résumé : A new approach to controlling the ensemble behavior of many identical agents is presented in this paper, inspired by motor recruitment in skeletal muscles. A group of finite state agents responds randomly to broadcast commands, each producing a state-dependent output that is measured in aggregate. Despite the lack of feedback signal and initial state information, this control architecture allows a single central controller to direct the aggregate output of the ensemble toward a desired value. First, the system is modeled as an ensemble of statistically independent, identically distributed, binary-state Markov processes with state transition probabilities designated by a central controller. Second, steady-state behavior, convergence rate, and variance of the aggregate output, i.e., the total number of recruited agents, are analyzed, and design trade-offs in terms of accuracy, convergence speed, and the number of spurious transitions are made. Third, a limited feedback signal, only detecting if the output has reached a goal, is added to the system, and the recruitment controller is designed as a stochastic shortest path problem. Optimal convergence rate and associated transition probabilities are obtained. Finally, the theoretical results are verified and demonstrated with both numerical simulation and control of an artificial muscle actuator made up of 60 binary shape memory alloy motor units. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

Adaptive control of mechanical gas face seals with rotor runout and static stator misalignment / Haojiong Zhang in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 10 p. Titre : Adaptive control of mechanical gas face seals with rotor runout and static stator misalignment Type de document : texte imprimé Auteurs : Haojiong Zhang, Auteur ; Robert G. Landers, Auteur ; Brad A. Miller, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Adaptive  control  Kalman  filters  Motion  estimation  Robust  control  Rotors  Seals  (stoppers)  Stators Index. décimale : 629.8 Résumé : This paper presents a control methodology that utilizes a robust model reference adaptive control technique to regulate the dynamic behavior of a coned mechanical gas face seal system in a flexibly mounted stator configuration. Individual adaptive controllers are designed for the three stator rigid body degrees of freedom based on the linear portions of their respective equations of motion. The force and moments generated within the gas film are estimated using Kalman filter-based estimators and directly cancelled in the control algorithm using offset control signals. The estimation errors are considered as bounded disturbances to the seal system and are taken into account by the robust adaptive controllers. Simulation results show that the controllers effectively stabilize the stator motion and control the stator tilts to synchronously track the rotor runout with near-zero relative misalignment magnitude and phase shift, thus, minimizing gas leakage. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...] [article] Adaptive control of mechanical gas face seals with rotor runout and static stator misalignment [texte imprimé] / Haojiong Zhang, Auteur ; Robert G. Landers, Auteur ; Brad A. Miller, Auteur . - 2010 . - 10 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 10 p. Mots-clés : Adaptive  control  Kalman  filters  Motion  estimation  Robust  control  Rotors  Seals  (stoppers)  Stators Index. décimale : 629.8 Résumé : This paper presents a control methodology that utilizes a robust model reference adaptive control technique to regulate the dynamic behavior of a coned mechanical gas face seal system in a flexibly mounted stator configuration. Individual adaptive controllers are designed for the three stator rigid body degrees of freedom based on the linear portions of their respective equations of motion. The force and moments generated within the gas film are estimated using Kalman filter-based estimators and directly cancelled in the control algorithm using offset control signals. The estimation errors are considered as bounded disturbances to the seal system and are taken into account by the robust adaptive controllers. Simulation results show that the controllers effectively stabilize the stator motion and control the stator tilts to synchronously track the rotor runout with near-zero relative misalignment magnitude and phase shift, thus, minimizing gas leakage. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013 [...]

An adjustable model reference adaptive control for a flexible launch vehicle / A. M. Khoshnood in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Titre : An adjustable model reference adaptive control for a flexible launch vehicle Type de document : texte imprimé Auteurs : A. M. Khoshnood, Auteur ; J. Roshanian, Auteur ; A. A. Jafari, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Adaptive  control  Aircraft  Flexible  structures  Stability  Vibration  control Index. décimale : 629.8 Résumé : Flexibility and aeroelastic behaviors in large space structures can lead to degradation of control system stability and performance. The model reference adaptive notch filter is an effective methodology used and implemented for reducing such effects. In this approach, designing a model reference for adaptive control algorithm in a flight device such as a launch vehicle is very important. In this way, the vibrations resulting from the structure flexibility mostly affects the pitch channel, and its influences on the yaw channel are negligible. This property is used and also the symmetrical behavior of the yaw and pitch channels. In this paper, by using this property and also the symmetrical behavior of the yaw and pitch channels, a new model reference using identification on the yaw channel is proposed. This model behaves very similar to the rigid body dynamic of the pitch channel and can be used as a model reference to control the vibrational effects. Simulation results illustrated applies the proposed algorithm and considerably reduces the vibrations in the pitch channel. Moreover, the main advantage of this new method is the online tuning of the model reference against unforeseen variations in the parameters of the rigid launch vehicle, which has not been considered in the previous works. Finally, robustness of the new control system in the presence of asymmetric behavior is investigated. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] An adjustable model reference adaptive control for a flexible launch vehicle [texte imprimé] / A. M. Khoshnood, Auteur ; J. Roshanian, Auteur ; A. A. Jafari, Auteur . - 2010 . - 07 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Mots-clés : Adaptive  control  Aircraft  Flexible  structures  Stability  Vibration  control Index. décimale : 629.8 Résumé : Flexibility and aeroelastic behaviors in large space structures can lead to degradation of control system stability and performance. The model reference adaptive notch filter is an effective methodology used and implemented for reducing such effects. In this approach, designing a model reference for adaptive control algorithm in a flight device such as a launch vehicle is very important. In this way, the vibrations resulting from the structure flexibility mostly affects the pitch channel, and its influences on the yaw channel are negligible. This property is used and also the symmetrical behavior of the yaw and pitch channels. In this paper, by using this property and also the symmetrical behavior of the yaw and pitch channels, a new model reference using identification on the yaw channel is proposed. This model behaves very similar to the rigid body dynamic of the pitch channel and can be used as a model reference to control the vibrational effects. Simulation results illustrated applies the proposed algorithm and considerably reduces the vibrations in the pitch channel. Moreover, the main advantage of this new method is the online tuning of the model reference against unforeseen variations in the parameters of the rigid launch vehicle, which has not been considered in the previous works. Finally, robustness of the new control system in the presence of asymmetric behavior is investigated. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

Dahl model-based hysteresis compensation and precise positioning control of an XY parallel micromanipulator with piezoelectric actuation / Qingsong Xu in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 12 p. Titre : Dahl model-based hysteresis compensation and precise positioning control of an XY parallel micromanipulator with piezoelectric actuation Type de document : texte imprimé Auteurs : Qingsong Xu, Auteur ; Yangmin, LI., Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Feedback  Feedforward  Hysteresis  Micromanipulators  Particle  swarm  optimisation  Piezoelectric  actuators  Position  control  Three-term  control Index. décimale : 629.8 Résumé : This paper presents a new control scheme for the hysteresis compensation and precise positioning of a piezoelectrically actuated micromanipulator. The scheme employs an inverse Dahl model-based feedforward in combination with a repetitive proportional-integral-derivative feedback control algorithm along with an antiwindup strategy. The dynamic model of the system with Dahl hysteresis is established and identified through particle swarm optimization approach. The necessity of using global optimization and how to choose the model parameters to be optimized are addressed as well. The effectiveness of the proposed controller is demonstrated by several experimental studies on an XY parallel micromanipulator. Experimental results reveal that both antiwindup and repetitive control strategies can improve the positioning accuracy of the system, and a well performance of the proposed scheme for both one-dimensional tracking and two-dimensional contouring tasks of the micromanipulator is achieved. Moreover, due to a simple structure, the proposed methodology can be easily generalized to other micro- or nanomanipulators with piezoelectric actuation as well. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://acatalogue_2.biblio.intranet.enp.edu.dz/catalog.php?categ=serials&sub=ana [...] [article] Dahl model-based hysteresis compensation and precise positioning control of an XY parallel micromanipulator with piezoelectric actuation [texte imprimé] / Qingsong Xu, Auteur ; Yangmin, LI., Auteur . - 2010 . - 12 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 12 p. Mots-clés : Feedback  Feedforward  Hysteresis  Micromanipulators  Particle  swarm  optimisation  Piezoelectric  actuators  Position  control  Three-term  control Index. décimale : 629.8 Résumé : This paper presents a new control scheme for the hysteresis compensation and precise positioning of a piezoelectrically actuated micromanipulator. The scheme employs an inverse Dahl model-based feedforward in combination with a repetitive proportional-integral-derivative feedback control algorithm along with an antiwindup strategy. The dynamic model of the system with Dahl hysteresis is established and identified through particle swarm optimization approach. The necessity of using global optimization and how to choose the model parameters to be optimized are addressed as well. The effectiveness of the proposed controller is demonstrated by several experimental studies on an XY parallel micromanipulator. Experimental results reveal that both antiwindup and repetitive control strategies can improve the positioning accuracy of the system, and a well performance of the proposed scheme for both one-dimensional tracking and two-dimensional contouring tasks of the micromanipulator is achieved. Moreover, due to a simple structure, the proposed methodology can be easily generalized to other micro- or nanomanipulators with piezoelectric actuation as well. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://acatalogue_2.biblio.intranet.enp.edu.dz/catalog.php?categ=serials&sub=ana [...]

Enhanced performance and stability in pneumatic servosystems with supplemental mechanical damping / Keith W. Wait in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 08 p. Titre : Enhanced performance and stability in pneumatic servosystems with supplemental mechanical damping Type de document : texte imprimé Auteurs : Keith W. Wait, Auteur ; Goldfarb, Michael, Auteur Année de publication : 2010 Article en page(s) : 08 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Damping  Pneumatic  actuators  Servomechanisms  Stability  Vibration  control Index. décimale : 629.8 Résumé : The authors present a model-based analysis of a position-velocity-acceleration-controlled pneumatic actuator that indicates that supplementing the pneumatic actuator with mechanical damping can significantly increase the gain margin, tracking accuracy, and disturbance rejection of a closed-loop-controlled pneumatic servoactuator. In order to validate the model-based analysis and purported performance and stability benefits provided by supplemental damping, experiments were performed on a single-degree-of-freedom pneumatic servosystem. Measurements conducted on the experimental setup, which validate the respective improvements in stability margin, tracking accuracy, and disturbance rejection, are described. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Enhanced performance and stability in pneumatic servosystems with supplemental mechanical damping [texte imprimé] / Keith W. Wait, Auteur ; Goldfarb, Michael, Auteur . - 2010 . - 08 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 08 p. Mots-clés : Damping  Pneumatic  actuators  Servomechanisms  Stability  Vibration  control Index. décimale : 629.8 Résumé : The authors present a model-based analysis of a position-velocity-acceleration-controlled pneumatic actuator that indicates that supplementing the pneumatic actuator with mechanical damping can significantly increase the gain margin, tracking accuracy, and disturbance rejection of a closed-loop-controlled pneumatic servoactuator. In order to validate the model-based analysis and purported performance and stability benefits provided by supplemental damping, experiments were performed on a single-degree-of-freedom pneumatic servosystem. Measurements conducted on the experimental setup, which validate the respective improvements in stability margin, tracking accuracy, and disturbance rejection, are described. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

H [infinity] control for continuous-time switched linear systems / Grace S. Deaecto in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Titre : H [infinity] control for continuous-time switched linear systems Type de document : texte imprimé Auteurs : Grace S. Deaecto, Auteur ; José C. Geromel, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Control  system  synthesis  Feedback  Linear  matrix  inequalities  Linear  systems  Lyapunov  methods  Stability Index. décimale : 629.8 Résumé : This paper deals with the output feedback H[infinity] control design problem for continuous-time switched linear systems. More specifically, the main goal is to design a switching rule together with a dynamic full order linear controller to satisfy a prespecified H[infinity] level defined by the [script L]2 gain from the input to the output signal. Initially, the state feedback version of this problem is solved in order to put in evidence the main difficulties we have to face toward the solution of the output feedback control design problem. The results reported in this paper are based on the so called Lyapunov–Metzler inequalities, which express a sufficient condition for switched linear systems global stability. The solution of the previously mentioned output feedback control design problem through a linear matrix inequality based method is the main contribution of the present paper. An academic example borrowed from literature is used for illustration. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] H [infinity] control for continuous-time switched linear systems [texte imprimé] / Grace S. Deaecto, Auteur ; José C. Geromel, Auteur . - 2010 . - 07 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Mots-clés : Control  system  synthesis  Feedback  Linear  matrix  inequalities  Linear  systems  Lyapunov  methods  Stability Index. décimale : 629.8 Résumé : This paper deals with the output feedback H[infinity] control design problem for continuous-time switched linear systems. More specifically, the main goal is to design a switching rule together with a dynamic full order linear controller to satisfy a prespecified H[infinity] level defined by the [script L]2 gain from the input to the output signal. Initially, the state feedback version of this problem is solved in order to put in evidence the main difficulties we have to face toward the solution of the output feedback control design problem. The results reported in this paper are based on the so called Lyapunov–Metzler inequalities, which express a sufficient condition for switched linear systems global stability. The solution of the previously mentioned output feedback control design problem through a linear matrix inequality based method is the main contribution of the present paper. An academic example borrowed from literature is used for illustration. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

Robust fault-tolerant control for a class of nonlinear stochastic systems with variance constraints / Lifeng Ma in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 06 p. Titre : Robust fault-tolerant control for a class of nonlinear stochastic systems with variance constraints Type de document : texte imprimé Auteurs : Lifeng Ma, Auteur ; Zidong Wang, Auteur ; Yuming Bo, Auteur Année de publication : 2010 Article en page(s) : 06 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Actuators  Control  system  synthesis  Covariance  analysis  Fault  tolerance  Linear  matrix  inequalities  Nonlinear  control  systems  Robust  control  Stochastic  systems Index. décimale : 629.8 Résumé : This paper is concerned with the variance-constrained controller design problem for a class of uncertain nonlinear stochastic systems with possible actuator faults. The stochastic nonlinearities described by statistical means are quite general that include several well-studied classes of nonlinearities as special cases. A model of actuator failures is adopted, which is more practical than the traditional outage one. A linear matrix inequality (LMI) approach is proposed to solve the multiobjective fault-tolerant controller design problem, where both the exponential stability and the steady-state state variance indices are simultaneously guaranteed. Within the developed LMI framework, a sufficient condition for the solvability of the robust control problem is obtained. The explicit expression of the desired controllers is also parameterized and a single degree-of-freedom model is used to demonstrate the effectiveness and applicability of the proposed design approach. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Robust fault-tolerant control for a class of nonlinear stochastic systems with variance constraints [texte imprimé] / Lifeng Ma, Auteur ; Zidong Wang, Auteur ; Yuming Bo, Auteur . - 2010 . - 06 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 06 p. Mots-clés : Actuators  Control  system  synthesis  Covariance  analysis  Fault  tolerance  Linear  matrix  inequalities  Nonlinear  control  systems  Robust  control  Stochastic  systems Index. décimale : 629.8 Résumé : This paper is concerned with the variance-constrained controller design problem for a class of uncertain nonlinear stochastic systems with possible actuator faults. The stochastic nonlinearities described by statistical means are quite general that include several well-studied classes of nonlinearities as special cases. A model of actuator failures is adopted, which is more practical than the traditional outage one. A linear matrix inequality (LMI) approach is proposed to solve the multiobjective fault-tolerant controller design problem, where both the exponential stability and the steady-state state variance indices are simultaneously guaranteed. Within the developed LMI framework, a sufficient condition for the solvability of the robust control problem is obtained. The explicit expression of the desired controllers is also parameterized and a single degree-of-freedom model is used to demonstrate the effectiveness and applicability of the proposed design approach. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

A disturbance attenuation approach for a class of continuous piecewise affine systems / A. Doris in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Titre : A disturbance attenuation approach for a class of continuous piecewise affine systems Titre original : control design and experiments Type de document : texte imprimé Auteurs : A. Doris, Auteur ; van de Wouw, N., Auteur ; W. P. M. H. Heemels, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Asymptotic  stability  Beams  (structures)  Closed  loop  systems  Continuous  systems  Convergence,  feedback  Frequency  response  Observers  Vibration  control Index. décimale : 629.8 Résumé : We consider the disturbance attenuation problem for a class of continuous piecewise affine systems. Hereto, observer-based output-feedback controllers are proposed that render the closed-loop system uniformly convergent. The convergence property ensures, first, stability and, second, the existence of a unique, bounded, globally asymptotically stable steady-state solution for each bounded disturbance. The latter property is key in uniquely specifying closed-loop performance in terms of disturbance attenuation. Because of its importance in engineering practice, the class of harmonic disturbances is studied in particular and performance measures for this class of disturbances are proposed based on so-called generalized frequency response functions for convergent systems. Additionally, the derived control strategy is extended by including conditions that guarantee the satisfaction of a bound on the control input. The effectiveness of the proposed control design strategy is illustrated by the application of the results to an experimental benchmark system being a piecewise affine beam system. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] A disturbance attenuation approach for a class of continuous piecewise affine systems = control design and experiments [texte imprimé] / A. Doris, Auteur ; van de Wouw, N., Auteur ; W. P. M. H. Heemels, Auteur . - 2010 . - 07 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 07 p. Mots-clés : Asymptotic  stability  Beams  (structures)  Closed  loop  systems  Continuous  systems  Convergence,  feedback  Frequency  response  Observers  Vibration  control Index. décimale : 629.8 Résumé : We consider the disturbance attenuation problem for a class of continuous piecewise affine systems. Hereto, observer-based output-feedback controllers are proposed that render the closed-loop system uniformly convergent. The convergence property ensures, first, stability and, second, the existence of a unique, bounded, globally asymptotically stable steady-state solution for each bounded disturbance. The latter property is key in uniquely specifying closed-loop performance in terms of disturbance attenuation. Because of its importance in engineering practice, the class of harmonic disturbances is studied in particular and performance measures for this class of disturbances are proposed based on so-called generalized frequency response functions for convergent systems. Additionally, the derived control strategy is extended by including conditions that guarantee the satisfaction of a bound on the control input. The effectiveness of the proposed control design strategy is illustrated by the application of the results to an experimental benchmark system being a piecewise affine beam system. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

Uncertainty propagation in abstracted systems via the Liouville equation / Patricia Mellodge in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 04 p. Titre : Uncertainty propagation in abstracted systems via the Liouville equation Type de document : texte imprimé Auteurs : Patricia Mellodge, Auteur ; Kachroo, Pushkin, Auteur Année de publication : 2010 Article en page(s) : 04 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Dynamics  Liouville  equation  Mechanical  engineering  Uncertain  systems Index. décimale : 629.8 Résumé : This technical brief shows that given a system and its abstraction, the evolution of uncertain initial conditions in the original system is, in some sense, matched by the evolution of the uncertainty in the abstracted system. In other words, it is shown that the concept of Phi-related vector fields extends to the case of stochastic initial conditions where the probability density function (pdf) for the initial conditions is known. In the deterministic case, the Phi mapping commutes with the system dynamics. In this paper, we show that in the case of stochastic initial conditions, the induced mapping Phipdf commutes with the evolution of the pdf according to the Liouville equation. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Uncertainty propagation in abstracted systems via the Liouville equation [texte imprimé] / Patricia Mellodge, Auteur ; Kachroo, Pushkin, Auteur . - 2010 . - 04 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 04 p. Mots-clés : Dynamics  Liouville  equation  Mechanical  engineering  Uncertain  systems Index. décimale : 629.8 Résumé : This technical brief shows that given a system and its abstraction, the evolution of uncertain initial conditions in the original system is, in some sense, matched by the evolution of the uncertainty in the abstracted system. In other words, it is shown that the concept of Phi-related vector fields extends to the case of stochastic initial conditions where the probability density function (pdf) for the initial conditions is known. In the deterministic case, the Phi mapping commutes with the system dynamics. In this paper, we show that in the case of stochastic initial conditions, the induced mapping Phipdf commutes with the evolution of the pdf according to the Liouville equation. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

Dynamic modeling and analysis of shield TBM cutterhead driving system / Xian Hong Li in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 4 (Juillet 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 14 p. Titre : Dynamic modeling and analysis of shield TBM cutterhead driving system Type de document : texte imprimé Auteurs : Xian Hong Li, Auteur ; Hai Bin Yu, Auteur ; Ming Zhe Yuan, Auteur Année de publication : 2010 Article en page(s) : 14 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Boring  machines  Construction  equipment  Cutting  tools  Gears  Tunnels Index. décimale : 629.8 Résumé : In this paper, a generalized nonlinear time-varying dynamic model is established for the cutterhead driving system of a shield tunnel boring machine. A nonlinear multiple input and multiple output state-space dynamic model is also proposed. The dynamic model is simulated to analyze the driving system and the effects of system parameters such as gear backlash and transmission error, larger gear inertia, and load torque on the dynamic response of driving system are investigated as well. A preliminary approach is proposed to restrain speed oscillation and reduce steady-state speed ripple. Through modeling and studying the dynamic model, we refine some important issues that should be given closer attention. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Dynamic modeling and analysis of shield TBM cutterhead driving system [texte imprimé] / Xian Hong Li, Auteur ; Hai Bin Yu, Auteur ; Ming Zhe Yuan, Auteur . - 2010 . - 14 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 4 (Juillet 2010) . - 14 p. Mots-clés : Boring  machines  Construction  equipment  Cutting  tools  Gears  Tunnels Index. décimale : 629.8 Résumé : In this paper, a generalized nonlinear time-varying dynamic model is established for the cutterhead driving system of a shield tunnel boring machine. A nonlinear multiple input and multiple output state-space dynamic model is also proposed. The dynamic model is simulated to analyze the driving system and the effects of system parameters such as gear backlash and transmission error, larger gear inertia, and load torque on the dynamic response of driving system are investigated as well. A preliminary approach is proposed to restrain speed oscillation and reduce steady-state speed ripple. Through modeling and studying the dynamic model, we refine some important issues that should be given closer attention. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

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