Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3230
2015-10-09T09:28:20ZA distributed attitude control law for formation flying based on the Cucker-smale model
http://hdl.handle.net/2117/26670
A distributed attitude control law for formation flying based on the Cucker-smale model
Paita, Fabrizio; Gómez Muntané, Gerard; Masdemont Soler, Josep
In this paper we consider the attitude synchronization problem for a swarm of spacecrafts flying in formation.
Starting from previous works on consensus dynamics, we construct a distributed attitude control law and derive analytically
sufficient conditions for the formation to converge asymptotically towards a synchronized, non–accelerating state (possibly defined a priori). Moreover, motivated by the results obtained on a particular consensus model, first introduced by F. Cucker and S. Smale to modellize the translational dynamics of flocks, we numerically explore
the dependence of the convergence process on the dimension of the formation and the relative initial conditions of the spacecrafts. Finally, we generalize the class of weights defined by the previous authors in order to dampen the aforementioned effects, thus making our control law suitable for very large formations.
2014-01-01T00:00:00ZMulti-agent linear dynamical systems, analyzing the consensus problem
http://hdl.handle.net/2117/25531
Multi-agent linear dynamical systems, analyzing the consensus problem
García Planas, María Isabel
In this paper the consensus problem is considered
for multi-agent systems having an independent agent
and fixed topology.
2014-01-01T00:00:00ZSymplectic and poisson structures with symmetries in interaction
http://hdl.handle.net/2117/24854
Symplectic and poisson structures with symmetries in interaction
Miranda Galcerán, Eva
Hamiltonian actions constitute a central object of study in symplectic
geometry. Special attention has been devoted to the toric case. Toric
symplectic manifolds provide natural examples of integrable systems
and every integrable system on a symplectic manifold is a toric manifold
in a neighbourhood of a compact fiber (Arnold–Liouville). The
classification of toric symplectic manifolds is given by Delzant’s theorem
in terms of the image of the moment map (Delzant polytope)....
2014-01-01T00:00:00ZUsing integral e-portfolio to learn linear algebra
http://hdl.handle.net/2117/24141
Using integral e-portfolio to learn linear algebra
García Planas, María Isabel; Taberna Torres, Judit
The use of e-portfolio is becoming common
in the learning and assessment of students. This is due to
the need of teachers to enhance student autonomy making
them to reflect on the process of learning. Lately, we have
worked with different software, facilitating its generation
and use. In this paper, the recent experience in the use of
e-portfolio for undergraduate students of the Universitat
Polit`ecnica de Catalunya are set.
2014-01-01T00:00:00ZIntroduction to Poisson Geometry
http://hdl.handle.net/2117/24114
Introduction to Poisson Geometry
Miranda Galcerán, Eva; Scott, Geoffrey
2014-01-01T00:00:00ZEl e-portafolio del estudiante en Mahara-Moodle y Google Sites
http://hdl.handle.net/2117/23534
El e-portafolio del estudiante en Mahara-Moodle y Google Sites
García Planas, María Isabel; Taberna Torres, Judit
Es bien conocido el potencial que tiene el uso del e-portfolio del estudiante para hacer visible tanto para el mismo como para los demás, de cómo y hasta que nivel ha logrado sus objetivos.
Para realizar un e-portafolio se pueden utilizar distintas aplicaciones, entre ellas se encuentran Google Sites y Mahara.
Google Sites permite de forma sencilla editando una plantilla previamente preparada por el profesor, crear una página web como muestra de sus trabajos desarrollados a lo largo de sus estudios.
Mahara es un sistema de e-portafolio que puede conectarse a Moodle y el cual puede ser controlado por el estudiante y puede ser visible por el grupo. Debido a la interoperabilidad de Mahara especialmente con Moodle, este permite que desde la plataforma de Atenea se puedan interconectar el profesorado con el e-portafolio del estudiante.
En este trabajo presentamos los resultados obtenidos desde el año 2011 hasta la actualidad en las investigaciones realizadas sobre el e-portafolio en el marco de la Universidad Politècnica de Catalunya.
2014-01-01T00:00:00ZAnalysis of control properties]{Analysis of control properties of convolutional concatenated codes under linear systems point of view
http://hdl.handle.net/2117/22684
Analysis of control properties]{Analysis of control properties of convolutional concatenated codes under linear systems point of view
García Planas, María Isabel; Um, Laurence Emilie; Souidi, El Mamoun
In this paper we consider two models of concatenated convolutional codes from
the perspective of linear systems theory. We present an input-state-output representation of these models
and we study the conditions for control properties as controllability, observability as well as output observability.
2013-01-01T00:00:00ZOn the cucker-smale flocking model applied to a formation moving in a central force field around the Earth
http://hdl.handle.net/2117/22420
On the cucker-smale flocking model applied to a formation moving in a central force field around the Earth
Paita, Fabrizio; Gomez Muntaner, Gerard; Masdemont Soler, Josep
The Cucker – Smale (CS) flocking model is an interacting particles control system where every particle adjusts
its dynamics according to a weighted average between its velocity and those of the other elements of the flock.
Under this model, a rigid body configuration can be achieved exponentially fast for suitable initial configurations.
Furthermore, as shown by J. Shen, if the dynamics of the formation is driven by the presence of a free willed leader
then similar asymptotic results can be obtained. In the present paper we extend the CS control law in the context of a
multi – spacecraft system moving around a central body. Some new analytical results are given, as well as the results
of the numerical explorations that have been done to evaluate the performances of the control law, with particular
attention to its interaction with a central gravitational field. These performances have been evaluated mainly through
the use of two indicators: the evolution of the relative spacecrafts distances and the total fuel expended to maintain
the formation.
2013-01-01T00:00:00ZJet Transport propagation of uncertainties for orbits around the Earth
http://hdl.handle.net/2117/21808
Jet Transport propagation of uncertainties for orbits around the Earth
Pérez, Daniel; Masdemont Soler, Josep; Gómez Muntané, Gerard
In this paper we present a tool to study the non-linear propagation of uncertainties for orbits around the Earth.
The tool we introduce is known as Jet Transport and allows to propagate full neighborhoods of initial states instead of
a single initial state by means of usual numerical integrators. The description of the transported neighborhood is ob-
tained in a semi-analytical way by means of polynomials in 6 variables. These variables correspond to displacements
in the phase space from the reference point selected in an orbit as initial condition. The basis of the procedure is a
standard numerical integrator of ordinary differential equations (such as a Runge-Kutta or a Taylor method) where
the usual arithmetic is replaced by a polynomial arithmetic. In this way, the solution of the variational equations is
also obtained up to high order. This methodology is applied to the propagation of satellite trajectories and to the
computation of images of uncertainty ellipsoids including high order nonlinear descriptions. The procedure can be
specially adapted to the determination of collision probabilities with catalogued space debris or for the end of life
analysis of spacecraft in Medium Earth Orbits
2013-01-01T00:00:00ZEnd-of-life disposal of libration point orbit spacecraft
http://hdl.handle.net/2117/21807
End-of-life disposal of libration point orbit spacecraft
Olikara, Zubin; Gómez Muntané, Gerard; Masdemont Soler, Josep
In this work we investigate end-of-life trajectories for
spacecraft in orbit about the Sun-Earth
L
1
and
L
2
libration points. A plan for decommission is often re-
quired during the mission design process. We study
the spacecraft's natural dynamics in both a high-
delity model and the circular restricted three-body
problem. In particular, we consider the role of the
unstable manifold and forbidden regions in determin-
ing disposal outcomes. A simple maneuver scheme
to prevent returns to the Earth vicinity is also an-
alyzed. We include discussion on potential collision
orbit schemes.
2013-01-01T00:00:00Z