Docta Complutense :: Browsing by Author "Cruz García, Jesús Manuel de la"

Browsing by Author "Cruz García, Jesús Manuel de la"

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A 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.
A helicopter control based on Eigenstructure assignment
(IEEE, 2006) Antequera, Nicolás; Santos Peñas, Matilde; Cruz García, Jesús Manuel de la
In this paper a controller based in the eigenvalues assignment technique is designed. Pie system to be stabilized is an unmanned helicopter. This eigenstructure based controller is designed considering all the measurable states. A LQ controller has also been applied to the same system in order to compare the responses regarding the robustness. The results are encouraging and prove that the eigenstructure assignment technique is useful for these nonlinear systems.
A loss-of-function mutation in the CFC domain of TDGF1 is associated with human forebrain defects
(Springer-Verlag, 2002-05) Cruz García, Jesús Manuel de la; Bamford, Richard N.; Burdine, Rebecca D.; Roessler, Erich; Barkovich, A. James; Donnai, Dian; Schier, Alexander F.; Muenke, Maximiliam
TDGF1 (CRIPTO) is an EGF-CFC family member and an obligate co-receptor involved in NODAL signaling, a developmental program implicated in midline, forebrain, and left-right axis development in model organisms. Previous studies of CFC1 (CRYPTIC), another member of the EGF-CFC family, demonstrated that normal function of this protein is required for proper laterality development in humans. Here we identify a mutation in the conserved CFC domain of TDGF1 in a patient with midtine anomalies of the forebrain. The mutant protein is inactive in a zebrafish rescue assay, indicating a role for TDGF1 in human midline and forebrain development.
A mathematical model for planning transportation of multiple petroleum products in a multi-pipeline system.
(Pergamon-Elsevier Science LTD, 2010-03-05) Cruz García, Jesús Manuel de la; Herrán, A.; Andrés Toro, Bonifacio de
A multiproduct Pipeline provides an economic way to transport large Volumes of refined petroleum products over long distances. In such a pipeline, different products are pumped back-to-back without any separation device between them. Sometimes, multiproduct pipelines can be connected together, resulting in a more complex system commonly named multi-pipeline system. This paper proposes a new discrete mathematical approach to solve short-term operational planning Of multi-pipeline systems for refined products. This model is based on a discrete approach that divides both the planning horizon into time intervals of equal duration and the individual polyducts into packages of equal volume each containing a single product. Numerical examples are solved in order to show the performance of the proposed model. All the instances are implemented with the OPL modeling language running CPLEX as solver.
A multiobjective optimization issue: genetic control planning or trajectories.
(World Scientific and Engineering Acad and Soc, 2005) Girón Sierra, José María; Fernández-Prisuelos, J.; Andrés Toro, Bonifacio de; Cruz García, Jesús Manuel de la
Part of a research project on cooperative marine robotics is the scenario of a submarine rendez-vous. This paper considers this case, where a high-manoeuvrability AUV (autonomous underwater vehicle) should meet a submarine platform for energy, samples and data service. Since the AUV is equipped with a set of thrusters, the problem of an adequate command of the thrusters appears. Given initial and final points for the AUV underwater trajectory, the question is to determine the set of forces and times to be exerted by the thrusters to get an adequate trajectory. Several constraints and simultaneous objectives to be optimized must be considered. Given the complexity of the multi-objective optimisation problem, it seems opportune to use Genetic Algorithms. The paper describes the problem to be solved, then explains how the GA were applied, and presents results for a set of cases considered, including obstacle avoidance.
A neuro-fuzzy approach to fast ferry vertical motion modelling
(Pergamon-Elsevier Science LTD, 2006-04) Santos Peñas, Matilde; López, R.; Cruz García, Jesús Manuel de la
In order to stabilise the motion of a high speed craft, and so to improve the comfort of the passengers and the crew while maintaining the speed, control-oriented model are needed. For this purpose, neuro-fuzzy systems have been used to obtain general models of the nonlinear behaviour of a fast ferry. The sources of the available knowledge are the physical laws of the vertical dynamics of the craft, and some experimental and simulated data of the ship performance. Two non-linear models focused on the vertical motion of the craft, both heave and pitch, are proposed: an academic one and a predictive one. The modelling task is complex and the results are original as the problem has not been previously solved in a general way neither by applying artificial intelligence techniques. The models have been proved satisfactory with regular and also irregular waves, and they have been used for ship control purposes. (C) 2005 Elsevier Ltd. All rights reserved.
A new expert system for greenness identification in agricultural images
(Pergamon-Elsevier Science LTD, 2013-05) Cruz García, Jesús Manuel de la; Romeo Granados, Juan; Pajares Martinsanz, Gonzalo; Montalvo Martínez, Martin; Guerrero Hernández, José Miguel; Guijarro Mata-García, Marta
It is well-known that one important issue emerging strongly in agriculture is related with the automation of tasks, where camera-based sensors play an important role. They provide images that must be conveniently processed. The most relevant image processing procedures require the identification of green plants, in our experiments they comes from barley and maize fields including weeds, so that some type of action can be carried out, including site-specific treatments with chemical products or mechanical manipulations. The images come from outdoor environments, which are affected for a high variability of illumination conditions because of sunny or cloudy days or both with high rate of changes. Several indices have been proposed in the literature for greenness identification, but under adverse environmental conditions most of them fail or do not work properly. This is true even for camera devices with auto-image white balance. This paper proposes a new automatic and robust Expert System for greenness identification. It consists of two main modules: (1) decision making, based on image histogram analysis and (2) greenness identification, where two different strategies are proposed, the first based on classical greenness identification methods and the second inspired on the Fuzzy Clustering approach. The Expert System design as a whole makes a contribution, but the Fuzzy Clustering strategy makes the main finding of this paper. The system is tested for different images captured with several camera devices. (C) 2012 Elsevier Ltd. All rights reserved.
A new learning strategy for stereo matching derived from a fuzzy clustering method
(Elsevier Science BV, 2000-03-16) Pajares Martinsanz, Gonzalo; Cruz García, Jesús Manuel de la
This paper presents an approach to the local stereo correspondence problem. The primitives or features used are groups of collinear connected edge points called segments. Each segment has several associated attributes or properties. We have verified that the differences of the attributes for the true matches cluster in a cloud around a center. Then for each current pair of primitives we compute a distance between the difference of its attributes and the cluster center. The correspondence is established in the basis of the minimum distance criterion (similarity constraint). We have designed an image understanding system to learn the best representative cluster center. For such purpose a new learning method is derived from the Fuzzy c-Means (FcM) algorithm where the dispersion of the true samples in the cluster is taken into account through the Mahalanobis distance. This is the main contribution of this paper. A better performance of the proposed local stereo-matching learning method is illustrated with a comparative analysis between classical local methods without learning.
A new wavelets image fusion strategy
(Springer-Verlag Berlin, 2003) Santos Peñas, Matilde; Pajares Martinsanz, Gonzalo; Portela, M.; Cruz García, Jesús Manuel de la
The aim of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image,,which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Different fusion methods have been proposed in the literature. This paper presents new methods based on the computation of local and global gradient. A comparative analysis is carried out against other existing strategies. The results are encouraging.
A probabilistic neural network for attribute selection in stereovision matching
(Springer-Verlag, 2002-10) Pajares Martinsanz, Gonzalo; Cruz García, Jesús Manuel de la
The key step in stereovision is image matching. This is carried out on the basis of selecting features, edge points, edge segments, regions, corners, etc. Once the features have been selected, a set of attributes (properties) for matching is chosen. This is a key issue in stereovision matching. This paper presents an approach for attribute selection in stereovision matching tasks based on a Probabilistic Neural Network, which allows the computation of a mean vector and a covariance matrix from which the relative importance of attributes for matching and the attribute interdependence can be derived. This is possible because the matching problem focuses on a pattern classification problem. The performance of the method is verified with a set of stereovision images and the results contrasted with a classical attribute selection method and also with the relevance concept.
A research on motion smoothing of fast ferries
(Pergamon-Elsevier Science LTD, 2002) Cruz García, Jesús Manuel de la; Pérez de Lucas, P.; Aranda, Joaquín; Girón Sierra, José María; Velasco, Francisco
This paper is about a research on the use of active appendages to smooth the motions of fast ferries. According to BAZAN specifications, the research focused on a fast ferry with a T-foil and transom flaps. A collaboration of three research groups, with the experimental support of CEHIPAR was established to accomplish the objectives. The research was scheduled as two main steps. A first step of control-oriented modelling has successfully been achieved. The second step is dedicated to control design and experimental evaluation, seeking for the best solution. First experimental results confirm good expectations with the use of the active controlled appendages. This paper describes the main aspects of the research: the problem to be solved, the methodology and fulfilment of the research project, and the most relevant results obtained.
A streamlined nonlinear path following kinematic controller
(IEEE Computer SOC, 2015) Cruz García, Jesús Manuel de la; López Orozco, José Antonio; Besada Portas, Eva; Aranda Almansa, Joaquín
This paper presents a new nonlinear path-following guidance method for autonomous vehicles, which integrates two guidance laws that have given good results independently in applications in autonomous ground, marine, and air vehicles. This new technique retains the best aspects of its two supporting methods, whereas it overcomes some of their drawbacks. It uses the control law by Park et al. to command the vehicle position towards a reference point. However, the position of the reference point is controlled in a different way: instead of being calculated to stay at a fixed distance forward of the vehicle, we use a strategy, inspired in the works by other authors, that controls the speed of the reference point to maintain its position at the given distance. This change does not increment the number of parameters to tune the algorithm and makes it applicable to any initial conditions and parameterized paths. The paper also analyzes the stability of this new nonlinear guidance control law and shows its effectiveness under different simulations.
A wavelet-based image fusion tutorial
(Pergamon-Elsevier Science LTD, 2004-09) Pajares Martinsanz, Gonzalo; Cruz García, Jesús Manuel de la
The objective of image fusion is to combine information from multiple images of the same scene. The result of image fusion is a new image which is more suitable for human and machine perception or further image-processing tasks such as segmentation, feature extraction and object recognition. Different fusion methods have been proposed in literature, including multiresolution analysis. This paper is an image fusion tutorial based on wavelet decomposition, i.e. a multiresolution image fusion approach. We can fuse images with the same or different resolution level, i.e. range sensing, visual CCD, infrared, thermal or medical. The tutorial performs a synthesis between the multi scale-decomposition-based image approach (Proc. IEEE 87 (8) (1999) 1315), the ARSIS concept (Photogramm. Eng. Remote Sensing 66 (1) (2000) 49) and a multisensor scheme (Graphical Models Image Process. 57 (3) (1995) 235). Some image fusion examples illustrate the proposed fusion approach. A comparative analysis is carried out against classical existing strategies, including those of multiresolution.
Adaptive parallel/serial sampling mechanisms for particle filtering in dynamic bayesian networks
(Springer-Verlag Berlin, 2010) Besada Portas, Eva; Cruz García, Jesús Manuel de la; Plis, Sergey M.; Lane, Terran
Monitoring the variables of real world dynamical systems is a difficult task due to their inherent complexity and uncertainty. Particle Filters (PF) perform that task, yielding probability distribution over the unobserved variables. However, they suffer from the curse of dimensionality problem: the necessary number of particles grows exponentially with the dimensionality of the hidden state space. The problem is aggravated when the initial distribution of the variables is not well known, as happens in global localization problems. In this paper we present two new adaptive sampling mechanisms for PFs for systems whose variable dependencies can be factored into a Dynamic Bayesian Network. The novel PFs, developed over the proposed sampling mechanisms, exploit the strengths of other existing PFs. Their adaptive mechanisms 1) modify or establish probabilistic links among the subspaces of hidden variables that are independently explored to build particles consistent with the current measurements and past history, and 2) tune the performance of the new PFs toward the behaviors of several existing PFs. We demonstrate their performance on some complex dynamical system estimation problems, showing that our methods successfully localize and track hidden states, and outperform some of the existing PFs.
An asynchronous, robust, and distributed multisensor fusion system for mobile robots
(Sage Publications INC, 2000-10) López Orozco, José Antonio; Cruz García, Jesús Manuel de la; Besada Portas, Eva; Ruipérez, P.
In this paper a multisensor fusion system that is used for calculating the position and orientation of an autonomous mobile robot is presented. The developed fusion system is distributed, robust, and asynchronous. IC is distributed to permit the parallel function of all the sensors. It is robust because, being distributed, the system has been designed to keep working properly in spite of the failure, removal, or change of any sense,: It is asynchronous to take advantage of the different features and rates of each sense,: The implementation of the system is based on the distributed Kalman filter developed by Durrant-Whyte and Rao. In that distributed filter, all the sensors work in parallel to obtain their own estimate based on their own observations and on the observations coming from other sensors. Changes have been made to simplify and speed up the computation of the external validation equations and to allow the use of any sensor model. The equations have also been adapted to deal with asynchronously operating sensors and with the existence of communication delays. The fusion system is used to estimate the position and orientation of a mobile robot. The performance of the fusion system is shown both under simulation and in a real test with a mobile robot.
Choquet Fuzzy Integral Applied to Stereovision Matching for Fish-Eye Lenses in Forest Analysis
(Springer-Verlag Berlin, 2009) Herrera Caro, Pedro Javier; Pajares Martinsanz, Gonzalo; Guijarro Mata-García, María; Ruz Ortíz, José Jaime; Cruz García, Jesús Manuel de la
This paper describes a novel stereovision matching approach based on omni-directional images obtained with fish-eye lenses in forest environments. The goal is to obtain a disparity map as a previous step for determining the volume of wood in the imaged area. The interest is focused on the trunks of the trees, due to the irregular distribution of the trunks; the most suitable features are the pixels. A set of six attributes is used for establishing the matching between the pixels in both images of the stereo pair. The final decision about the matched pixel is taken based on the Choquet Fuzzy Integral paradigm, which is a technique well tested for combining classifiers. The use and adjusting of this decision approach to our specific stereo vision matching problem makes the main finding of the paper. The procedure is based on the application of three well known matching constraints. The proposed approach is compared favourably against the usage of simple features and other fuzzy strategy that combines the simple ones.
Combination of attributes in stereovision matching for fish-eye lenses in forest analysis
(Springer-Verlag Berlin, 2009) Cruz García, Jesús Manuel de la; Herrera Caro, Pedro Javier; Pajares Martinsanz, Gonzalo; Guijarro Mata-García, María; Ruz Ortíz, José Jaime
This paper describes a novel stereovision matching approach by combining several attributes at the pixel level for omni-directional images obtained with fish-eye lenses in forest environments. The goal is to obtain a disparity map as a previous step for determining distances to the trees and then the volume of wood in the imaged area. The interest is focused on the trunks of the trees. Because of the irregular distribution of the trunks, the most suitable features are the pixels. A set of six attributes is used for establishing the matching between the pixels in both images of the stereo pair. The final decision about the matched pixels is taken by combining the attributes. Two combined strategies are proposed: the Sugeno Fuzzy Integral and the Dempster-Shafer theory. The combined strategies, applied to our specific stereo vision matching problem, make the main finding of the paper. In both, the combination is based on the application of three well known matching constraints. The proposed approaches are compared among them and favourably against the usage of simple features.
Combining support vector machines and simulated annealing for stereovision matching with fish eye lenses in forest environments
(Pergamon-Elsevier Science LTD, 2011-07) Cruz García, Jesús Manuel de la; Herrera Caro, Pedro Javier; Pajares Martinsanz, Gonzalo; Guijarro Mata-García, María
We present a novel strategy for computing disparity maps from omni-directional stereo images obtained with fish-eye lenses in forest environments. At a first segmentation stage, the method identifies textures of interest to be either matched or discarded. Two of them are identified by applying the powerful Support Vector Machines approach. At a second stage, a stereovision matching process is designed based on the application of four stereovision matching constraints: epipolarity, similarity, uniqueness and smoothness. The epipolarity guides the process. The similarity and uniqueness are mapped once again through the Support Vector Machines, but under a different way to the previous case; after this an initial disparity map is obtained. This map is later filtered by applying the Discrete Simulated Annealing framework where the smoothness constraint is conveniently mapped. The combination of the segmentation and stereovision matching approaches makes the main contribution. The method is compared against the usage of simple features and combined similarity matching strategies. (C) 2011 Elsevier Ltd. All rights reserved.
Control 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 la
After 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.
Courseware management tool for engineering education
(Int Inst Informatics & Systemics, 2002) López Orozco, José Antonio; Risco Martín, José Luis; Andrés Toro, Bonifacio de; Cruz García, Jesús Manuel de la
An courseware management tool has been designed and constructed in order to use as support in the education. The objective of this tool has been to build a template web to offer any subject. A simple database generation allows show the most important theoretical concepts, development exercises and practices, and the resolution of theoretical and practical tests. It includes exercises of checking and reinforcement, and guided practices. Theoretical, practical and problem tests allow the teacher to realize a follow-up of the student. The tool is reinforced with statistical study of these tests, discussion forums and direct communication between student and teacher for resolution of doubts so the pupil acquires the necessary foundations to deal subjects of higher courses. The courseware management tool has been applied for subjects of Control Systems in the new plans of study of the Universidad Complutense de Madrid (Electronic Engineering and Physical Sciences studies).

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