Documents disponibles écrits par cet auteur

Design, modeling, and motion control of the noncircular turning process for camshaft machining / Tsu-Chin, Tsao in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N° 3 (Mai/Juin 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N° 3 (Mai/Juin 2008) . - 07 p. Titre : Design, modeling, and motion control of the noncircular turning process for camshaft machining Type de document : texte imprimé Auteurs : Tsu-Chin, Tsao, Auteur ; Zongxuan Sun, Auteur ; Reed D. Hanson, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : noncircular  turning  process;  camshaft  machining Résumé : This paper presents the design, modeling, and motion control of the noncircular turning process for camshaft machining. The cam profile tracking performance requirements are first characterized to meet industry standards. Based on these requirements, a unique test fixture using state-of-the-art actuation and sensing technologies is designed for the noncircular turning process. Modeling of the electrohydraulic servo valve, actuator, and sensors is conducted based on their frequency responses. Digital motion control that achieves asymptotic cam profile tracking while maintaining system robust stability is designed and implemented on the turning test fixture. Spindle speed can be chosen depending on the required profile tracking accuracy with higher speed rendering higher machining rate for rough turning and lower speed rendering higher accuracy for finish turning. Experimental results of turning a variety of cam profiles show that the tracking error is less than 30μm for spindle speed at 300rpm and is less than 60μm for spindle speed at 600rpm or 1200rpm. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Mobile/article.aspx?article [...] [article] Design, modeling, and motion control of the noncircular turning process for camshaft machining [texte imprimé] / Tsu-Chin, Tsao, Auteur ; Zongxuan Sun, Auteur ; Reed D. Hanson, Auteur . - 2010 . - 07 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N° 3 (Mai/Juin 2008) . - 07 p. Mots-clés : noncircular  turning  process;  camshaft  machining Résumé : This paper presents the design, modeling, and motion control of the noncircular turning process for camshaft machining. The cam profile tracking performance requirements are first characterized to meet industry standards. Based on these requirements, a unique test fixture using state-of-the-art actuation and sensing technologies is designed for the noncircular turning process. Modeling of the electrohydraulic servo valve, actuator, and sensors is conducted based on their frequency responses. Digital motion control that achieves asymptotic cam profile tracking while maintaining system robust stability is designed and implemented on the turning test fixture. Spindle speed can be chosen depending on the required profile tracking accuracy with higher speed rendering higher machining rate for rough turning and lower speed rendering higher accuracy for finish turning. Experimental results of turning a variety of cam profiles show that the tracking error is less than 30μm for spindle speed at 300rpm and is less than 60μm for spindle speed at 600rpm or 1200rpm. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Mobile/article.aspx?article [...]

A Performance Enhancement Scheme for Robust Repetitive Control System / Byung-Sub, Kim in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 126 N° 1 (Mars 2004) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 126 N° 1 (Mars 2004) . - 224-229 p. Titre : A Performance Enhancement Scheme for Robust Repetitive Control System Titre original : Arrangement de Perfectionnement d'Exécution pour le Système de Commande Réitéré Robuste Type de document : texte imprimé Auteurs : Byung-Sub, Kim, Auteur ; Tsu-Chin, Tsao, Auteur Article en page(s) : 224-229 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Système  de  commade  réitéré  numérique  Structure  passe-bas  de  filtre  Générateur  de  signal  Stabilité  robuste  Exécution  robuste  Sensibilité  Déclancheur  électrohydraulique Index. décimale : 629.8 Résumé : This paper presents a method for enhancing the performance of a digital repetitive control system. The performance at the fundamental frequency and its harmonics of repetitive exogenous signals is improved by applying a modified low-pass q(z,z–1) filter structure in the repetitive signal generator of the internal model. Stability and robust performance is achieved through µ-synthesis. The modified low-pass filter is motivated by the attempt to reduce the sensitivity function by squaring it. The magnitude of the sensitivity function is substantially reduced at the periodic reference frequencies since the value is already much less than unity. The proposed approach is demonstrated by its implementation on an electrohydraulic actuator for tracking periodic cam-like profiles. Cet article présente une méthode pour augmenter l'exécution d'un système de commande réitéré numérique. L'exécution à la fréquence fondamentale et à ses harmoniques des signaux exogènes réitérés est améliorée en appliquant une structure passe-bas modifiée de filtre de q (z, z-1) dans le générateur de signal réitéré du modèle interne. La stabilité et l'exécution robuste est réalisée par la µ-synthèse. Le filtre passe-bas modifié est motivé par la tentative de réduire la fonction de sensibilité en l'ajustant. L'importance de la fonction de sensibilité est sensiblement réduite aux fréquences périodiques de référence puisque la valeur est déjà beaucoup moins que l'unité. L'approche proposée est démontrée par son exécution sur un déclencheur électrohydraulique pour dépister périodique came-comme des profils. En ligne : bkim@kimm.re.kr, ttsao@seas.ucla.edu [article] A Performance Enhancement Scheme for Robust Repetitive Control System = Arrangement de Perfectionnement d'Exécution pour le Système de Commande Réitéré Robuste [texte imprimé] / Byung-Sub, Kim, Auteur ; Tsu-Chin, Tsao, Auteur . - 224-229 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 126 N° 1 (Mars 2004) . - 224-229 p. Mots-clés : Système  de  commade  réitéré  numérique  Structure  passe-bas  de  filtre  Générateur  de  signal  Stabilité  robuste  Exécution  robuste  Sensibilité  Déclancheur  électrohydraulique Index. décimale : 629.8 Résumé : This paper presents a method for enhancing the performance of a digital repetitive control system. The performance at the fundamental frequency and its harmonics of repetitive exogenous signals is improved by applying a modified low-pass q(z,z–1) filter structure in the repetitive signal generator of the internal model. Stability and robust performance is achieved through µ-synthesis. The modified low-pass filter is motivated by the attempt to reduce the sensitivity function by squaring it. The magnitude of the sensitivity function is substantially reduced at the periodic reference frequencies since the value is already much less than unity. The proposed approach is demonstrated by its implementation on an electrohydraulic actuator for tracking periodic cam-like profiles. Cet article présente une méthode pour augmenter l'exécution d'un système de commande réitéré numérique. L'exécution à la fréquence fondamentale et à ses harmoniques des signaux exogènes réitérés est améliorée en appliquant une structure passe-bas modifiée de filtre de q (z, z-1) dans le générateur de signal réitéré du modèle interne. La stabilité et l'exécution robuste est réalisée par la µ-synthèse. Le filtre passe-bas modifié est motivé par la tentative de réduire la fonction de sensibilité en l'ajustant. L'importance de la fonction de sensibilité est sensiblement réduite aux fréquences périodiques de référence puisque la valeur est déjà beaucoup moins que l'unité. L'approche proposée est démontrée par son exécution sur un déclencheur électrohydraulique pour dépister périodique came-comme des profils. En ligne : bkim@kimm.re.kr, ttsao@seas.ucla.edu

Process feedback control of the noncircular turning process for camshaft machining / Zongxuan Sun in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N° 3 (Mai/Juin 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N° 3 (Mai/Juin 2008) . - 6 p. Titre : Process feedback control of the noncircular turning process for camshaft machining Type de document : texte imprimé Auteurs : Zongxuan Sun, Auteur ; Tsu-Chin, Tsao, Auteur Année de publication : 2010 Article en page(s) : 6 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : learning  controller;  nonlinear  systems Résumé : This paper presents a frequency domain learning control scheme for a class of nonlinear systems and its application to the process feedback control of the noncircular turning process for camshaft machining. In frequency domain, periodic signals are represented by the Fourier expansions that are nonzero only at discrete frequency points. An input dependent system matrix can be used to describe the input-output relationship of a class of nonlinear systems with periodic input and output signals. A learning controller is designed based on the system matrix and the bound of unmodeled dynamics. Conditions to achieve asymptotic stability and tracking performance are derived. To further improve system robustness, a low pass filter is used to turn off the learning scheme at high frequencies. The learning control scheme is then applied to the process feedback control of camshaft machining using the noncircular turning process. A two level control structure is adopted. The first level is servo control that ensures precise tool slide motion. The second level is frequency domain learning control that compensates machined profile errors due to the effects of tool/workpiece geometry, tool wears, machine deformations, and spindle runout errors. Relationship between the servo control and learning control is discussed. Implementation of the process feedback control on a steel camshaft turning demonstrates improvement of the maximum cam profile errors from 80μm to within 20μm in five iterations. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Mobile/article.aspx?article [...] [article] Process feedback control of the noncircular turning process for camshaft machining [texte imprimé] / Zongxuan Sun, Auteur ; Tsu-Chin, Tsao, Auteur . - 2010 . - 6 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N° 3 (Mai/Juin 2008) . - 6 p. Mots-clés : learning  controller;  nonlinear  systems Résumé : This paper presents a frequency domain learning control scheme for a class of nonlinear systems and its application to the process feedback control of the noncircular turning process for camshaft machining. In frequency domain, periodic signals are represented by the Fourier expansions that are nonzero only at discrete frequency points. An input dependent system matrix can be used to describe the input-output relationship of a class of nonlinear systems with periodic input and output signals. A learning controller is designed based on the system matrix and the bound of unmodeled dynamics. Conditions to achieve asymptotic stability and tracking performance are derived. To further improve system robustness, a low pass filter is used to turn off the learning scheme at high frequencies. The learning control scheme is then applied to the process feedback control of camshaft machining using the noncircular turning process. A two level control structure is adopted. The first level is servo control that ensures precise tool slide motion. The second level is frequency domain learning control that compensates machined profile errors due to the effects of tool/workpiece geometry, tool wears, machine deformations, and spindle runout errors. Relationship between the servo control and learning control is discussed. Implementation of the process feedback control on a steel camshaft turning demonstrates improvement of the maximum cam profile errors from 80μm to within 20μm in five iterations. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Mobile/article.aspx?article [...]

Saturation-induced instability and its avoidance in adaptive control of hard disk drives / Néstor O. Perez-Arancibia in IEEE Transactions on control systems technology, Vol. 18 N° 2 (Mars 2010) 

Public ISBD [article]  in IEEE Transactions on control systems technology > Vol. 18 N° 2 (Mars 2010) . - pp. 368-382 Titre : Saturation-induced instability and its avoidance in adaptive control of hard disk drives Type de document : texte imprimé Auteurs : Néstor O. Perez-Arancibia, Auteur ; Tsu-Chin, Tsao, Auteur ; James S. Gibson, Auteur Année de publication : 2011 Article en page(s) : pp. 368-382 Note générale : Génie Aérospatial Langues : Anglais (eng) Mots-clés : Control-signal  saturation  Frequency  weighting  Hard  disk  drive  (HDD)  Iterative  adaptative  tuning  Minimum  variance  adaptive  control Index. décimale : 629.1 Résumé : This paper presents an investigation of the design and implementation of minimum-variance adaptive controllers for computer hard disk drive (HDD) read-write track following. A common characteristic of minimum-variance controllers, adaptive or not, is that they rely on prediction filters with large high- frequency gains to predict broadband disturbances, and this often produces control-signal saturation and eventual loss of stability. Two methods are introduced here to address this issue. The first method, suitable for online adaptive control, uses frequency weighting to constrain the high-frequency gain of the prediction filter. The second method, suitable for tuning fixed-gain controllers, employs an adaptive scheme iteratively over a finite duration. Both methods were implemented on a commercial hard disk drive, and experimental results demonstrate their effectiveness. DEWEY : 629.1 ISSN : 1063-6536 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5229135 [article] Saturation-induced instability and its avoidance in adaptive control of hard disk drives [texte imprimé] / Néstor O. Perez-Arancibia, Auteur ; Tsu-Chin, Tsao, Auteur ; James S. Gibson, Auteur . - 2011 . - pp. 368-382. Génie Aérospatial Langues : Anglais (eng) in IEEE Transactions on control systems technology > Vol. 18 N° 2 (Mars 2010) . - pp. 368-382 Mots-clés : Control-signal  saturation  Frequency  weighting  Hard  disk  drive  (HDD)  Iterative  adaptative  tuning  Minimum  variance  adaptive  control Index. décimale : 629.1 Résumé : This paper presents an investigation of the design and implementation of minimum-variance adaptive controllers for computer hard disk drive (HDD) read-write track following. A common characteristic of minimum-variance controllers, adaptive or not, is that they rely on prediction filters with large high- frequency gains to predict broadband disturbances, and this often produces control-signal saturation and eventual loss of stability. Two methods are introduced here to address this issue. The first method, suitable for online adaptive control, uses frequency weighting to constrain the high-frequency gain of the prediction filter. The second method, suitable for tuning fixed-gain controllers, employs an adaptive scheme iteratively over a finite duration. Both methods were implemented on a commercial hard disk drive, and experimental results demonstrate their effectiveness. DEWEY : 629.1 ISSN : 1063-6536 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5229135