Person: Esteban San Román, Segundo
Esteban San Román
Universidad Complutense de Madrid
Faculty / Institute
Arquitectura de Computadores y Automática
Arquitectura y Tecnología de Computadores
Now showing 1 - 10 of 17
PublicationMEGARA, the R=6000-20000 IFU and MOS of GTC(SPIE-Int Soc Optical Engineering, 2018) Gil de Paz, Armando; Gallego Maestro, Jesús; Bouquin, A.; Carbajo, J.; Cardiel López, Nicolás; Castillo Morales, África; Esteban San Román, Segundo; López Orozco, José Antonio; Pascual, S.; Picazo, P.; Sánchez Penim, Ainhoa; Velázquez, M.; Zamorano Calvo, Jaime; Catalán Torrecilla, Cristina; Dullo, Bililign; Pérez González, P.G.; Roca Fábrega, SantiMEGARA is the new generation IFU and MOS optical spectrograph built for the 10.4m Gran Telescopio CANARIAS (GTC). The project was developed by a consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain). The instrument arrived to GTC on March 28th 2017 and was successfully integrated and commissioned at the telescope from May to August 2017. During the on-sky commissioning we demonstrated that MEGARA is a powerful and robust instrument that provides on-sky intermediate-to-high spectral resolutions R_(FWHM) ~ 6,000, 12,000 and 20,000 at an unprecedented efficiency for these resolving powers in both its IFU and MOS modes. The IFU covers 12.5 x 11.3 arcsec2 while the MOS mode allows observing up to 92 objects in a region of 3.5 x 3.5 arcmin^(2) . In this paper we describe the instrument main subsystems, including the Folded-Cassegrain unit, the fiber link, the spectrograph, the cryostat, the detector and the control subsystems, and its performance numbers obtained during commissioning where the fulfillment of the instrument requirements is demonstrated. PublicationA fast autonomous scaled ship for experimental seakeeping control studies(IEEE, 2005) Esteban San Román, Segundo; Recas Piorno, Joaquín; Girón Sierra, José María; Cruz García, Jesús Manuel de la; Riola, J. M.A second part of our research on the seakeeping control in fast ferries, is devoted to general heading and sea state conditions. Although scaled ships are basis for experimental studies, it is not possible to keep using them in towing tanks. The main reason is that high speeds require large space for experiments, so towing tanks are not large enough. This has been noticed after the first part of our research, with head seas, in a 150m x 30m towing tank with wavemaker. Consequently, we are preparing for open air experiments. A new fast autonomous scaled ship has been developed. She is self-propelled, and is self-governed by an embedded PC on-board. The ship carries sensors for heading, speed and seakeeping control. Several scaled moving appendages have been added: two transom flaps, two lateral fins, and a T-foil. The ship uses two scaled waterjets, which also control the heading: the ship has no rudder. A distributed monitoring and control system has been designed and implemented for on-board operation. All equipment has to be very light, since the real fast ferry that we reproduce at 1/40 scale is aluminium made. A digital radio link has been provided for distant off-shore monitoring. The paper describes the autonomous ship, the on-board monitoring and control system, and shows several experimental results with quiet waters and with several types of waves. PublicationExperimental framework for autonomous fast ships's control design(World Scientific and Engineering Acad and Soc, 2005) Recas Piorno, Joaquín; Esteban San Román, Segundo; Girón Sierra, José María; Cruz García, Jesús Manuel de laThe research on seakeeping control of fast ships requires difficult experiments for modeling and control design. To alleviate the ship motion certain active appendages are added, such moving flaps, T-foil and fins. The motion of appendages must be optimized to counteract each encountered wave. During our first research steps, a scaled down ship, with scaled appendages, has been used in a towing tank facility. The scaled ship is towed at fixed speeds of experimental interest, for instance at the equivalent to 40 knots. The wavemaker in the towing tank is used to generate specified waves. Along the experiments it was noticed that the towing of the replica spoils certain expected phenomena. A more appropriate way of doing experiments to observe all ship motions, is to use an autonomous self-propelled scaled ship. In this paper a new autonomous scaled ship is presented. It contains an on-board control system, so the ship is self-governed. Complex maneuvering can be programmed for certain study interests. Our autonomous ship is linked via radio with an external monitoring system. The ship and the off-shore monitoring system constitute an experimental framework for advanced studies about fast ship control. PublicationControl code generator used for control experiments in ship scale model.(Pergamon-Elsevier Science LTD, 2002) Polo, O. R.; Esteban San Román, Segundo; Marón, A.; Grau, L.; Cruz García, Jesús Manuel de laAfter a study of control design to get a good candidate for testing, it comes a step of experimental confirmation. The general objective of the research is to smooth the vertical motions of a fast ferry. A T-foil and transom flaps are added to a scaled-down replica of the fast ferry. These appendages can move under control. So there is a control system installed on the replica, that moves the appendages using motors, and measures the main variables of the ship and actuators motions. This control system is based on an industrial PC with electronic interfaces for motors and sensors. The control algorithm obtained by the design, must be implemented as real-time control software, to be executed on the industrial PC. For a fast and easy translation from design to real-time application, a new software tool has been developed. This tool generates directly C++ code, easy to compile, from a graphical description of the control. With this tool, the experiments have been achieved in short time. During experiments, several non expected circumstances appear, but this was not a problem: the tool allows for an easy improvement of the original design. The paper describes the tool and its use during experiments. PublicationDevelopment of a control-oriented model of the vertical motions of a fast ferry(Soc Naval Arch Marine Eng, 2004-09) Esteban San Román, Segundo; Girón Sierra, José María; Andrés Toro, Bonifacio de; Cruz García, Jesús Manuel de laAs a main part of a research study on the control of active flaps and a T-foil of a high-speed ferry, a control-oriented model of vertical motions of the ship has been developed. The objective of the control is to improve comfort, decreasing the impact of heave and pitch motions. We have experimental data from a towing tank institution and simulations with PRECAL. The model is based on a decomposition of the physic phenomena into two main aspects: the coupling of the ship with distance between waves and the dynamics of a semisubmerged mass. The model can be handled with MATLAB-SIMULINK, which is useful for studying control strategies. The model shows good agreement (model validation) with the experimental and simulated data for regular and irregular waves. The article shows a methodology, based on MATLAB tools, for obtaining control-oriented models from computer-aided design (CAD)-based programs. That means that the control-oriented model can be derived from the ship design, even before the ship is built. PublicationFrequency-domain analysis for prediction of seasickness on ships(Soc Naval arch Marine Eng, 2005-10) Esteban San Román, Segundo; Girón Sierra, José María; Recas Piorno, Joaquín; Cruz García, Jesús Manuel de laOscillatory vertical motions of ships cause seasickness. There is a mathematical model that can be used to compute the percent of passengers who will get sick caused by vertical motions, However, the application of the mathematical model requires obtaining 2 hours of records of experimental or simulated ship motion data. Based on a filters analogy, this article proposes a new frequency-domain method for the calculation of seasickness incidence. The method can be applied to any sea power spectrum and any ship. Because it is based on response amplitude operators or transfer functions, which can be obtained with seakeeping simulation programs, the method can be applied even before the ship is built. The results of the method can be useful for ship design and for the analysis of best operation for passenger comfort. PublicationDistributed electronic system for monitoring and control of a fast ship physical model(IEEE, 2003) Girón Sierra, José María; Esteban San Román, Segundo; Recas Piorno, Joaquín; Andrés Toro, Bonifacio de; Besada Portas, Eva; Cruz García, Jesús Manuel de laThis paper is related with a research on vertical motion alleviation of fast ferries. A scaled down replica of a fast ferry was built, for experimental studies in a towing tank facility. Some submerged moving actuators were added to the replica: a pair of transom flaps, lateral fins and a T-foil near the bow. Two series of experiments with waves generated in a large basin must be done. One of the series is devoted to modelling, and the second for model-based control studies. Due to the fast motions of the experimental ship, it is not possible to attach it to a computerized carriage with instrumentation (it is part of the towing tank facility). Instead, the experimental ship must be autonomous, with all monitoring and control systems on board. Since there are six motions of the ship to be considered, the number of on-board sensors and actuators, and the complexity of control, take us to decide the design of a distributed electronic system. It is based on a central embedded PC, several microcomputer nodes, and the CANbus. The on board system interacts, using a wireless data link, with an off-shore experiment control and data processing system, with an interesting visualization performance. The purpose of the paper is to introduce this system and the associated experimental framework. PublicationEDROOM. Automatic C++ code generator for real time systems modelled with room(Pergamon-Elsevier Science LTD, 2002) Polo, O. R.; Cruz García, Jesús Manuel de la; Girón Sierra, José María; Esteban San Román, SegundoThe development of real-time control systems is usually part of a design cycle, involving implementation, experimental control system testing, and re-design. For a faster and better complete development, a software engineering approach, based on a modelling language, is recommended. A successful alternative is ROOM: a modelling language with a graphical syntax. In this paper EdROOM is presented: an environment developed to graphically edit ROOM models and to automatically generate, from the models, C++ real-time control code for direct experimental application. The code generated is modular and easy to debug. The paper describes the design of the environment, with the key aspects of the modelling methodology. EdROOM has been used by our research team for several applications, with satisfactory results. One of these applications concerns the control of actuators of a fast ship for vertical motion smoothing: this is described as an example of EdROOM use. PublicationMEGARA, the new intermediate-resolution optical IFU and MOS for GTC: getting ready for the telescope(SPIE-Int Soc Optical Engineering, 2016) Gil de Paz, Armando; Gallego Maestro, Jesús; Cardiel López, Nicolás; Castillo Morales, África; Cruz García, Jesús Manuel de la; Esteban San Román, Segundo; López Orozco, José Antonio; Pascual, S.; Picazo, P.; Sánchez-Penim, A.; Zamorano Calvo, Jaime; Pérez González, Pablo Guillermo; otros, ...MEGARA (Multi-Espectrografo en GTC de Alta Resolucion para Astronomia) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4m telescope in La Palma that is being built by a Consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain), and UPM (Spain). The instrument is currently finishing AIV and will be sent to GTC on November 2016 for its on-sky commissioning on April 2017. The MEGARA IFU fiber bundle (LCB) covers 12.5x11.3 arcsec(2) with a spaxel size of 0.62 arcsec while the MEGARA MOS mode allows observing up to 92 objects in a region of 3.5x3.5 arcmin(2) around the IFU. The IFU and MOS modes of MEGARA will provide identical intermediate-to-high spectral resolutions (R-FWHM similar to 6,000, 12,000 and 18,700, respectively for the low-, mid-and high-resolution Volume Phase Holographic gratings) in the range 3700-9800 angstrom angstrom. An x-y mechanism placed at the pseudo-slit position allows (1) exchanging between the two observing modes and (2) focusing the spectrograph for each VPH setup. The spectrograph is a collimator-camera system that has a total of 11 VPHs simultaneously available (out of the 18 VPHs designed and being built) that are placed in the pupil by means of a wheel and an insertion mechanism. The custom-made cryostat hosts a 4kx4k 15-mu m CCD. The unique characteristics of MEGARA in terms of throughput and versatility and the unsurpassed collecting are of GTC make of this instrument the most efficient tool to date to analyze astrophysical objects at intermediate spectral resolutions. In these proceedings we present a summary of the instrument characteristics and the results from the AIV phase. All subsystems have been successfully integrated and the system-level AIV phase is progressing as expected. PublicationFirst scientific observations with MEGARA at GTC(Spie-Int Soc Optical Engineering, 2018) Gil de Paz, Armando; Gallego Maestro, Jesús; Bouquin, A.; Carbajo, J.; Cardiel López, Nicolás; Castillo Morales, África; Esteban San Román, Segundo; López Orozco, José Antonioi; Pascual Ramírez, Sergio; Picazo, P.; Sánchez Penim, Ainhoa; Zamorano Calvo, Jaime; Catalán Torrecilla, Cristina; Dullo, Bililign; Pérez González, P.G.On June 25th 2017, the new intermediate-resolution optical IFU and MOS of the 10.4-m GTC had its first light. As part of the tests carried out to verify the performance of the instrument in its two modes (IFU & MOS) and 18 spectral setups (identical number of VPHs with resolutions R=6000-20000 from 0.36 to 1 micron) a number of astronomical objects were observed. These observations show that MEGARA@GTC is called to fill a niche of high-throughput, intermediate resolution IFU & MOS observations of extremely-faint narrow-lined objects. Lyman-α absorbers, star-forming dwarfs or even weak absorptions in stellar spectra in our Galaxy or in the Local Group can now be explored to a new level. Thus, the versatility of MEGARA in terms of observing modes and spectral resolution and coverage will allow GTC to go beyond current observational limits in either depth or precision for all these objects. The results to be presented in this talk clearly demonstrate the potential of MEGARA in this regard.