Predictive extended state observer-based repetitive controller for uncertain systems with input delay

This article presents a predictive extended state observer-based repetitive controller (PESO-RC) to simultaneously track and reject periodic signals on systems with long input delay and parameter uncertainties. First, a novel extended state observer (ESO) is proposed to tackle periodic signals on processes with input delay. Then a simple low pass filter is incorporated and tuned to improve robustness against modelling errors. Moreover, the modified repetitive controller (MRC) is integrated to enhance the performance when compensating periodic signals without affecting the overall system’s stability. Stability criteria and robust stability analysis under modelling errors are studied to develop tuning guidelines. Furthermore, validation of the proposed controller and comparison studies are simulated in MATLAB and tested on a brushless DC servo motor which highlight the superior performance of PESO-RC

A robust design of time-varying internal model principle-based control for ultra-precision tracking in a direct-drive servo stage

This paper proposes a robust design of the time-varying internal model principle-based control (TV-IMPC) for tracking sophisticated references generated by linear time-varying (LTV) autonomous systems. The existing TV-IMPC design usually requires a complete knowledge of the plant I/O (input/output) model, leading to the lack of structural robustness. To tackle this issue, we, in the paper, design a gray-box extended state observer (ESO) to estimate and compensate unknown model uncertainties and external disturbances. By means of the ESO feedback, the plant model is kept as nominal, and hence the structural robustness is achieved for the time-varying internal model. It is shown that the proposed design has bounded ESO estimation errors, which can be further adjusted by modifying the corresponding control gains. To stabilize the ESO-based TV-IMPC, a time-varying stabilizer is developed by employing Linear Matrix Inequalities (LMIs). Extensive simulation and experimental studies are conducted on a direct-drive servo stage to validate the proposed robust TV-IMPC with ultra-precision tracking performance ($\sim 60$nm RMSE out of $\pm80$mm stroke)

Aktive Reduktion modulierter Zahneingriffsvibrationen von Planetengetrieben

Der Forschungsbeitrag ist motiviert durch die vermehrte Anwendung von Planetengetrieben in neuen Technologien wie Getriebefan-Triebwerken. Das Ziel der Arbeit besteht darin, die Luft- und Körperschallemissionen von Planetengetrieben mithilfe eines Systems zur aktiven Schwingungsreduktion (ASR) zu reduzieren. Dies ermöglicht einerseits Komfortsteigerungen für Menschen durch Lärmreduktion und andererseits den Schutz empfindlicher Bauteile vor schädigenden Vibrationen. Eine Literaturrecherche macht Herausforderungen in Bezug auf Modellbildung, Regelalgorithmen und Aktorik durch den hohen Frequenzbereich des Zahneingriffs deutlich. ASR-Produkte nach dem aktuellen Stand der Technik funktionieren nur für deutlich tiefere Frequenzen. Zur messtechnischen Charakterisierung des Anregungsverhaltens von Planetengetrieben in der Leistungsklasse bis 10kW erfolgt der Aufbau eines Prüfstands. Dieser erlaubt die Ermittlungvon technischen und psychoakustischen Anforderungen an das zu entwickelnde ASR-System. Vier ausgewählte modellfreie Regelalgorithmen werden zur Kompensation modulierter Vibrationen aus Planetengetrieben weiterentwickelt. Eine einheitliche Simulationsumgebung erlaubt die Gegenüberstellung der Algorithmen. Der schmalbandig wirkende Simultaneous-Equations-Algorithmus wird ausgewählt. Eine Methode zur Auslegung von piezoelektrischen Inertialmassenaktoren (IMA) wird vorgestellt und angewendet. Zur Realisierung des ASR-Systems werden verschiedene Konzepte vorgeschlagen und diskutiert. Ein Konzept mit vier IMA in tangentialer Anordnung am Getriebegehäuse wird ausgelegt, konstruiert und am Prüfstand als Aktormodul aufgebaut. In Prüfstandsversuchen wird der entwickelte modellfreie Regelalgorithmus validiert. Er erzielt vergleichbare Regelgüten wie der modellbasierte FxLMSAlgorithmus, bei gleichzeitig größerer Robustheit gegenüber Regelstreckenänderungen. Das entwickelte Aktormodul ermöglicht signifikante Reduktionen verschiedener Regelgrößen wie Schalldruck, Beschleunigung oder Kraft. In den meisten untersuchten Konfigurationen ergeben sich deutliche Reduktionen der Regelgrößen, während andere Schwingungsgrößen verschlechtert werden. Die akustische Abstrahlung einer mit dem Getriebe verbundenen Platte kann auf Restamplituden von 18% verringert werden. Durch eine Reduktion von Lautheit und Tonhaltigkeit wird das Getriebegeräusch angenehmer wahrgenommen. Eine Diskussion von Potentialen und Aufwänden des ASR-Systems schließt die Arbeit ab

Abstracts on Radio Direction Finding (1899 - 1995)

The files on this record represent the various databases that originally composed the CD-ROM issue of "Abstracts on Radio Direction Finding" database, which is now part of the Dudley Knox Library's Abstracts and Selected Full Text Documents on Radio Direction Finding (1899 - 1995) Collection. (See Calhoun record https://calhoun.nps.edu/handle/10945/57364 for further information on this collection and the bibliography). Due to issues of technological obsolescence preventing current and future audiences from accessing the bibliography, DKL exported and converted into the three files on this record the various databases contained in the CD-ROM. The contents of these files are: 1) RDFA_CompleteBibliography_xls.zip [RDFA_CompleteBibliography.xls: Metadata for the complete bibliography, in Excel 97-2003 Workbook format; RDFA_Glossary.xls: Glossary of terms, in Excel 97-2003 Workbookformat; RDFA_Biographies.xls: Biographies of leading figures, in Excel 97-2003 Workbook format]; 2) RDFA_CompleteBibliography_csv.zip [RDFA_CompleteBibliography.TXT: Metadata for the complete bibliography, in CSV format; RDFA_Glossary.TXT: Glossary of terms, in CSV format; RDFA_Biographies.TXT: Biographies of leading figures, in CSV format]; 3) RDFA_CompleteBibliography.pdf: A human readable display of the bibliographic data, as a means of double-checking any possible deviations due to conversion

Applicable Solutions in Non-Linear Dynamical Systems

From Preface: The 15th International Conference „Dynamical Systems - Theory and Applications” (DSTA 2019, 2-5 December, 2019, Lodz, Poland) gathered a numerous group of outstanding scientists and engineers who deal with widely understood problems of theoretical and applied dynamics. Organization of the conference would not have been possible without great effort of the staff of the Department of Automation, Biomechanics and Mechatronics of the Lodz University of Technology. The patronage over the conference has been taken by the Committee of Mechanics of the Polish Academy of Sciences and Ministry of Science and Higher Education of Poland. It is a great pleasure that our event was attended by over 180 researchers from 35 countries all over the world, who decided to share the results of their research and experience in different fields related to dynamical systems. This year, the DSTA Conference Proceedings were split into two volumes entitled „Theoretical Approaches in Non-Linear Dynamical Systems” and „Applicable Solutions in Non-Linear Dynamical Systems”. In addition, DSTA 2019 resulted in three volumes of Springer Proceedings in Mathematics and Statistics entitled „Control and Stability of Dynamical Systems”, „Mathematical and Numerical Approaches in Dynamical Systems” and „Dynamical Systems in Mechatronics and Life Sciences”. Also, many outstanding papers will be recommended to special issues of renowned scientific journals.Cover design: Kaźmierczak, MarekTechnical editor: Kaźmierczak, Mare

The music of Tomas Marco: a holistic approach, with particular regard to selected works for violin: volume 1

This
 thesis
 presents
 a
 holistic
 approach
 to
 the
 music
 and
 life
 of
 the
 Spanish
 contemporary
 composer
 Tomás
 Marco 
(b.
1942).
Such 
an
 approach
combines 
a
 number
 of
 interconnected
 perspectives
 (historical,
 sociological,
 philosophical,
 analytical
 and
 performative)
 that
 aim
 to
 provide
 a
 general
 picture
 of
 Marco’s
 music
 and
 intellectuality,
 proposing
 over‐arching
 analytical
 frameworks
 that
 take
 as 
a
 point
 of
 departure,
 but
 go
 beyond,
 the
 consideration
 of
 a
 selection
 of
 Marco’s 
works
 for
 violin. The
 lack
 of
 scholarship
 on
 Marco
 in
 English
 makes
 necessary
 a
 biographical
 introduction,
 presented
 in
 Chapter
 1:
 a
 number
 of
 crucial
 historical
 and
 sociological
 elements
 are 
considered
 in 
order 
to 
develop 
a
critical
 perspective 
on
 Marco’s
 life
 and
 oeuvre.
 Chapter
 2
 analyses
 Marco’s
 relationship,
 during
 the
 1960s,
 with
 the
 avant‐garde
 Spanish
 musical
 movement
 ZAJ.
 It
 traces
 the
 parallelisms
 between
 ZAJ
 and
 Fluxus,
 considers
 its
 political
 dimension
 and
 explores
 its 
influence
 on
 the 
formation
of 
Marco’s 
mature 
musical 
idiom. 
Chapter
 3 examines
 the 
connections
between 
Marco’s 
thinking 
and 
Theodor 
W. 
Adorno’s and
 Henri‐Louis
 Bergson’s
 philosophies.
 Such
 analysis
 seeks,
 ultimately,
 to
 uncover Marco’s
consideration 
of 
time
 and
 its 
relationship 
with 
specific 
elements
 of
their 
philosophical 
worlds,
which 
will 
work 
as 
the 
basis
 for 
the 
development
 and 
application 
of 
a 
number 
of 
time‐related 
analytical 
perspectives, 
in
Chapter 
4,
 on
 Marco’s
 works
 Umbral
 de
 la
 Desolación,
 Dúo
 Concertante
 nº
 3,
 Dúo
 Concertante 
nº
6 
and 
Iris.
 Performance
 plays 
a 
key 
role 
in
 those 
analytical 
perspectives:
 I 
include 
my
own
 recording
 of 
Marco’s 
works, used 
both 
as 
analytical 
material 
and 
to
introduce 
the
 centrality 
of 
the 
performative 
side
 of 
music, as 
its 
realisation
through 
time, 
in 
the
 consideration 
and
 analysis 
of 
musical 
time.
 A
 second
 volume, consisting
 of
 an 
important
 collection
 of
 material
 on
 which
 a
 significant 
part
 of
 the
 arguments
 developed
 throughout
 the
 thesis 
are
based,
 is
 included 
for 
two 
main 
reasons: 
the 
lack 
of 
material 
in 
English, 
and
the 
hope 
that
 this 
research
 project 
might 
ignite 
an 
interest 
in 
Marco’s 
work
and
 the
 world 
of
 Spanish 
contemporary 
music
 to 
which 
the 
annexed
material 
is 
clearly 
relevant