DSpace Collection:
http://hdl.handle.net/2117/115
2014-08-22T11:48:36ZPhase-Locked Loop using a comb filter with fractional delay
http://hdl.handle.net/2117/12709
Title: Phase-Locked Loop using a comb filter with fractional delay
Authors: Griñó Cubero, Robert; Mughal, Umair Najeeb
Abstract: A Phase Locked Loop is a feedback system combining a Voltage Controlled Oscillator and a Phase Comparator These are connected so that the oscillator maintains a constant phase angle relative to a reference signal. Phase locked loops can be used, for example to generate stable output frequency signals from a fixed frequency signal.
A Comb Filter is a kind of Notch Filter (Non Recursive Filter) that is normally used to remove the harmonic terms from a particular signal.
In this Design, a PLL is implemented using a Comb Filter because the main frequencies that are considered noise in the PLL loop are the harmonics of the fundamental frequency.
There are 2 objectives of this project report,
1. Implementing Comb Filter Using Fractional Delay
2. Comparision of Frame Based and Typical Discrete Sample Based Implementation of a Comb Filter2011-06-06T11:14:49ZPeriodic solutions with nonconstant sign in Abel equations of the second kind
http://hdl.handle.net/2117/11572
Title: Periodic solutions with nonconstant sign in Abel equations of the second kind
Authors: Martínez-Seara Alonso, M. Teresa; Ros Oton, Xavier; Olm Miras, Josep Maria
Abstract: The study of periodic solutions with constant sign in the Abel equation of the second kind can be made through
the equation of the first kind. This is because the situation is equivalent under the transformation x 7¡æ x.1, and
there
are many results available in the literature for the first kind equation. However, the equivalence breaks down when
one seeks for solutions with nonconstant sign. This note is devoted to periodic solutions with nonconstant sign in
Abel equations of the second kind. Specifically, we obtain sufficient conditions to ensure the existence of a periodic
solution that shares the zeros of the leading coefficient of the Abel equation. Uniqueness and stability features of
such
solutions are also studied2011-02-28T12:26:34ZOn the role of virtual laboratories in an undergraduate power electronics introductory course
http://hdl.handle.net/2117/7048
Title: On the role of virtual laboratories in an undergraduate power electronics introductory course
Authors: Biel Solé, Domingo; Vento Maldonado, Jorge; Costa Castelló, Ramon2010-04-22T10:05:02ZNon-uniform sampling in digital repetitive control systems: An LMI stability analysis
http://hdl.handle.net/2117/2651
Title: Non-uniform sampling in digital repetitive control systems: An LMI stability analysis
Authors: Ramos Fuentes, Germán Andrés; Olm Miras, Josep Maria; Costa Castelló, Ramon
Abstract: Digital repetitive control is a technique which allows to track periodic references and/or reject periodic disturbances. Repetitive controllers are usually designed assuming a fixed frequency for the signals to be tracked/rejected, its main drawback being a dramatic performance decay when this frequency varies. A usual approach to overcome the problem consists of an adaptive change of the sampling time according to the reference/disturbance period variation. This report presents a stability analysis of a digital repetitive controller working under time-varying sampling period by means of an LMI gridding approach. Theoretical developments are illustrated with experimental results.2009-03-12T09:50:11ZRobust Exact Differentiation via Sliding Mode Technique applied to a Fixed-Frequency Quasi-Sliding Control Algorithm
http://hdl.handle.net/2117/2360
Title: Robust Exact Differentiation via Sliding Mode Technique applied to a Fixed-Frequency Quasi-Sliding Control Algorithm
Authors: Biel Solé, Domingo; Fossas Colet, Enric; Meza Benavides, Carlos; Muñoz Aguilar, Raúl Santiago
Abstract: This paper presents the design of a DC-AC power converter controller that bears the same benefits of a sliding mode controller but with the advantage of a fixed-frequency control signal. The controller is based on the imposition of zero averaged value of the sliding surface in each switching cycle. A keypoint of the presented controller is the calculation of the sliding surface’s derivative which in the present paper is obtained using an estimation algorithm introduced by Levant in 1998.2008-11-13T15:10:55ZIterative approximation of unstable limit cycles for a class of Abel equations
http://hdl.handle.net/2117/1384
Title: Iterative approximation of unstable limit cycles for a class of Abel equations
Authors: Fossas Colet, Enric; Olm Miras, Josep Maria; Sira-Ramírez, Hebertt
Abstract: This report considers the analytical approximation of unstable limit cycles that may appear in Abel equations written in the normal form. The procedure uses an iterative approach that takes advantage of the contraction mapping theorem. Thus, the obtained sequence exhibits uniform convergence to the target periodic solution. The effectiveness of the technique is illustrated through the approximation of an unstable limit cycle that appears in an Abel equation arising in a tracking control problem that affects an elementary, nonminimum phase, second order bilinear power converter.2007-11-28T11:57:54ZAnálisis y diseño de controladores lineales para el convertidos elevador ("boost") bidireccional en corriente
http://hdl.handle.net/2117/531
Title: Análisis y diseño de controladores lineales para el convertidos elevador ("boost") bidireccional en corriente
Authors: Malo Barragán, Shane Leonardo; Griñó Cubero, Robert
Abstract: Los convertidores de voltaje DC-DC juegan dentro de la tecnología actual un papel fundamental, actúan como puentes de transferencia de energía entre fuentes y cargas, ambas de corriente continua, que no son compatibles por naturaleza, por ejemplo, una carga puede necesitar ser alimentada con un potencial “v” mientras que la fuente disponible provee un voltaje “v1“que puede ser mayor o menor a “v”. El convertidor “Boost” o “Elevador” ofrece especial interés, pues como su nombre lo indica, puede proveer en su salida un voltaje mayor al que posea en la entrada y que además es de implementación relativamente simple. Es de vital interés el conocer las limitaciones que se tienen para controlar el comportamiento de este tipo de dispositivos, para esto se creará un modelo del sistema que permita conocer las restricciones con las que se cuenta al trabajar con estas estructuras.2006-10-31T10:53:24ZHybrid model of a doubly-fed induction machine and back-to-back converter
http://hdl.handle.net/2117/519
Title: Hybrid model of a doubly-fed induction machine and back-to-back converter
Authors: Batlle Arnau, Carles; Dòria Cerezo, Arnau; Fossas Colet, Enric
Abstract: This report details the port interconnection of two subsystems: a power electronics subsystem (a back-to-back AC/AC converter (B2B), coupled to a phase of the power grid), and an electromechanical subsystem (a doubly-fed induction machine (DFIM), coupled mechanically to a flywheel and electrically to the power grid and to a local varying load). Both subsystems have been essentially described in previous reports (deliverables D 0.5 and D 4.3.1), although some previously unpublished details are presented here. The B2B is a variable structure system (VSS), due to the presence of control-actuated switches; however, from a modelling and simulation, as well as a control-design, point of view, it is sensible to consider modulated transformers (MTF in the bong-graph language) instead of the pairs of complementary switches. The port-Hamiltonian models of both subsystems are presented and coupled through a power-preserving interconnection, and the Hamiltonian description of the whole system is obtained; detailed bond-graphs of all the subsystems and the complete system are provided.2006-10-23T14:35:20ZA repetitive controller for discrete-time passive systems
http://hdl.handle.net/2117/518
Title: A repetitive controller for discrete-time passive systems
Authors: Costa Castelló, Ramon; Griñó Cubero, Robert
Abstract: This work proposes and studies a new repetitive controller for discrete-time systems which are required to track or to attenuate periodic signals. The main characteristic of the proposed controller is its passivity. This fact implies closed-loop stable behaviour when it is used with discrete-time passive plants. The work also discusses the energetic structure, the frequency response and the time response of the proposed controller structure. Some examples are included to illustrate its practical use.2006-10-23T14:07:36ZAplicacions interactives per la docència de control amb computador: alguns exemples de llaç obert
http://hdl.handle.net/2117/513
Title: Aplicacions interactives per la docència de control amb computador: alguns exemples de llaç obert
Authors: Fàbregas i Cornellà, Josep
Abstract: En aquest treball s’han desenvolupat un conjunt que poden ésser de gran utilitat per il•lustrat els diferents aspectes de la teoria presentada en l’assignatura “Control amb Computador” de l’ETSEIB. Aquestes eines són un conjunt d’aplicacions individuals cadascuna d’elles pensades per un concepte concret. Aquestes aplicacions han estat desenvolupades amb el programa SysQuake. SysQuake és un programa orientat a la simulació i a la visualització de dades científiques. A través d’un ús innovador de gràfics interactius. SysQuake proporciona eines necessàries per a la resolució de problemes matemàtics complexes.
Aquest document conté una descripció funcional de les diferents aplicacions (fitxes) que pot servir com manual d’usuari de cadascuna d’elles.2006-10-19T11:24:22ZIrrigation canal system identification for control purposes
http://hdl.handle.net/2117/512
Title: Irrigation canal system identification for control purposes
Authors: Sepúlveda Toepfer, Carlos; Rodellar Benedé, José
Abstract: This report gives some guidance on how to obtain black-box models of irrigation canal reaches, using system identification techniques.
First of all, some general properties of the irrigation canal reaches are deducted, based on the use of the linearized Sain-Venant equations to model the water behavior.
Then different aspects of the system identification procedure like the sampling time, the model structure, the experiment design, etc., are studied, in order to avoid possible modelling problems and, in that manner, obtain a good linear model capable to be used in control systems designs.
The results obtained in the time domain and the frequency domain show that one can achieve very accurate models, if the system identification procedure is designed with care having in mind the intrinsic properties of the system.
The research reveals that it is not convenient to perform a black-box irrigation canal system identification, without having a certain knowledge of the system.2006-10-19T09:41:25ZIdentification of a system with dry friction
http://hdl.handle.net/2117/511
Title: Identification of a system with dry friction
Authors: Iurian, Claudiu; Ikhouane, Fayçal; Rodellar Benedé, José; Griñó Cubero, Robert
Abstract: A new elasto-plastic state variable friction model is proposed which models both stiction and presliding displacement. However, the proposed Leuven model by Swevers et al. is more complex than the standard parameterization of the LuGre model due to the use of an hybrid hysteresis model and therefore more difficult to be used for control design and analysis. On the other hand, the elasto-plastic state variable friction model proposed by Dupont et al. is mainly based on simulation studies and the presented ideas are not yet confirmed experimentally. Hence, the standard parameterization of the LuGre model is still most wildly used nowadays.2006-10-17T11:04:56ZRobust Hamiltonian passive control for higher relative degree outpus
http://hdl.handle.net/2117/482
Title: Robust Hamiltonian passive control for higher relative degree outpus
Authors: Batlle Arnau, Carles; Dòria Cerezo, Arnau; Fossas Colet, Enric
Abstract: We present an improvement of the well-know Interconnection and Damping Assignment-Passivity-based Control (IDA-PBC) technique. The IDA-PBC method is based on the Port –controlled Hamiltonian Systems description and requires the knowledge of the full energy (or Hamiltonian) function. This is a problem because, in general, the equilibrium point which is to be regulated depends on uncertain parameters. In this paper, we show how select the target port-Hamiltonian structure so that this dependence is reduced. This new approach allows to improve the robustness for higher relative degree outputs, and, for illustration purposes, is applied to a simple academic nonlinear system2006-09-18T12:38:38ZOn preserving passivity in sampled-data linear systems
http://hdl.handle.net/2117/417
Title: On preserving passivity in sampled-data linear systems
Authors: Costa Castelló, Ramon; Fossas Colet, Enric
Abstract: Passivity is a well know phenomenon in several engineering areas. Due to its interesting properties, it is used in several areas of control engineering. Generally, this property is lost under direct discretization. In this work a new methodology which allows to preserve continuous-time passivity is presented. This methodology is based on choosing a proper output, which preserves the passivity structure, while keeping the continuous-time energy function. Analytic formulation and numerical examples, both open and close loop, are provided in the paper.2006-07-05T12:04:30ZModeling and control of electromechanical systems
http://hdl.handle.net/2117/416
Title: Modeling and control of electromechanical systems
Authors: Batlle Arnau, Carles; Dòria Cerezo, Arnau
Abstract: The material presented in the these notes covers the sessions Modelling
of electromechanical systems, Passive control theory I and Passive
control theory II of the II EURON/GEOPLEX Summer School on Modelling and
Control of Complex Dynamical Systems.
We start with a general description of what an electromechanical system
is from a network modelling point of view. Next, a general formulation in
terms of PHDS is introduced, and some of the previous electromechanical
systems are rewritten in this formalism. Power converters, which are
variable structure systems (VSS), can also be given a PHDS form.
We conclude the modelling part of these lectures with a rather complex
example, showing the interconnection of subsystems from several domains,
namely an arrangement to temporally store the surplus energy in a
section of a metropolitan transportation system based on dc motor
vehicles, using either arrays of supercapacitors or an electric powered
flywheel. The second part of the lectures addresses control of PHD
systems. We first present the idea of control as power connection of a
plant and a controller. Next we discuss how to circumvent this obstacle
and present the basic ideas of Interconnection and Damping Assignment
(IDA) passivity-based control of PHD systems.2006-07-05T11:35:33Z