Improved underwater stereo reconstruction by turbidity characterization

[Resumen] Este trabajo se centra en realizar un completo análisis de imágenes de objetos característicos en entornos subacuáticos con diferentes grados de turbidez, con el objetivo de mejorar la calidad de las imágenes que faciliten el posterior reconocimiento de objetos y cálculo de su posición respecto al vehículo subacuático mediante técnicas de visión estereoscópica. Para ello, se ha analizado el comportamiento de un conjunto de evaluadores de la calidad mediante una batería de imágenes tomadas con distintos niveles de turbidez para posteriormente poder determinar la influencia de las técnicas de filtrado en la correspondencia estéreo. De esta manera, se puede obtener una reconstrucción más densa de los objetos que permita determinar con mayor precisión la posición de estos con referencia al vehículo subacuático y servir tanto de ayuda al operador humano como para la generación de trayectorias de navegación autónoma.[Abstract] This work focuses on performing a complete image analysis of characteristic objects in underwater environments with different degrees of turbidity, with the aim of improving the quality of the images to facilitate the subsequent recognition of objects and calculation of their position with respect to the underwater vehicle using stereoscopic vision techniques. For this purpose, the behavior of a set of quality evaluators has been analyzed using a battery of images taken with different levels of turbidity in order to determine the influence of filtering techniques on the stereo correspondence. In this way, a denser reconstruction of the objects can be obtained, allowing to determine their position with reference to the underwater vehicle with greater precision and to serve both as an aid to the human operator and for the generation of autonomous navigation trajectories.Ministerio de Ciencia e Innovación; TED2021-132158B-I0

Dynamic positioning of floating caissons based on the UKF filter under external perturbances induced by waves

This paper presents a dynamic positioning control scheme for concrete caissons in an attempt to automate part of the manoeuvres which usually require a complex deploy of personnel and equipment for port infrastructures development. The aim of this paper is to propose a control scheme, which is able to provide a reduction in costs and an improvement in security for the dynamic positioning manoeuvres . To do so, a dual loop controller is developed and the unscented Kalman filter is applied for states and perturbances estimation. Furthermore, a control allocation algorithm is proposed based on anchoring lines and winches. Finally, some simulations are performed to verify the effectiveness of the proposed approach.The Spanish FEDER/Ministry of Science, Innovation and Universities — State Research Agency (Fig. 14) is greatly acknowledged for funding our research through SAFE Project (Desarrollo de un Sistema Autónomo para el Fondeo de Estructuras para Obras Marítimas), Grant Agreement: RTC-2017-6603-4. The authors would like to thank FCC CO as a collaborator in the development of the SAFE Project. R. Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities

LQG control for dynamic positioning of floating caissons based on the Kalman filter

This paper presents the application of an linear quadratic gaussian (LQG) control strategy for concrete caisson deployment for marine structures. Currently these maneuvers are carried out manually with the risk that this entails. Control systems for these operations with classical regulators have begun to be implemented. They try to reduce risks, but they still need to be optimized due to the complexity of the dynamics involved during the sinking process and the contact with the sea bed. A linear approximation of the dynamic model of the caisson is obtained and an LQG control strategy is implemented based on the Kalman filter (KF). The results of the proposed LQG control strategy are compared to the ones given by a classic controller. It is noted that the proposed system is positioned with greater precision and accuracy, as shown in the different simulations and in the Monte Carlo study. Furthermore, the control efforts are less than with classical regulators. For all the reasons cited above, it is concluded that there is a clear improvement in performance with the control system proposed.The Spanish FEDER/Ministry of Science, Innovation and Universities—State Research Agency is greatly acknowledged for partially funding our research through the SAFE Project (Desarrollo de un Sistema Autónomo para el Fondeo de Estructuras para Obras Marítimas), GrantAgreement: RTC-2017-6603-4. The Regional Ministry of Universities, Equality, Culture and Sports of the Gov-ernment of Cantabria has supported this work through the ControlFond project (Control De Ve-hículos Subacuáticos No Tripulados Para Supervisión De Estructuras Para Obras Marítimas Fondeadas). The authors would like to thank FCC Construcción CO as a collaborator in the de-velopment of the SAFE Project, specially Victor Florez Casillas and Nuria Cotallo Aguado (Tech-nical Direction/Hydraulic and Maritime Works) and Alvaro de Toro Mingo (Machinery Direction). R. Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Analysis and valuation of production of refrigeration equipment

Grado en Ingeniería en Tecnologías Industriale

Dynamic positioning of floating caissons in maritime works

En la presente tesis se expone la investigación llevada a cabo con el objetivo de realizar el posicionamiento dinámico de cajones flotantes en obras marítimas. Se ha realizado una revisión del estado del conocimiento y se han estudiado las principales características del modelo del cajón. Por otra parte, se han estudiado las perturbaciones principales como son las olas y el viento. Además, se estudian e implementan métodos de filtrado de Kalman (KF) y ‘’Unscented Kalman Filter’’ (UKF). Tras esto, se han presentado diversos algoritmos de control. Destaca la aplicación de algoritmos de control básico, control óptimo (LQR), control predictivo basado en modelos (MPC) y control adaptativo L1. Por último, se ha realizado una comparativa de resultados y se han expuesto las significativas mejoras que se obtienen con la aplicación de algunos de estos controladores.This thesis presents the research carried out with the aim of performing the dynamic positioning of floating caissons in maritime works. A review of the state of the art has been made and the main characteristics of the caisson model have been studied. Furthermore, the main disturbances such as waves and wind have been evaluated. In addition, Kalman filtering (KF) and Unscented Kalman Filter (UKF) methods are studied and implemented. Then, several control algorithms have been presented. The application of basic control, optimal control (LQR), model predictive control (MPC) and L1 adaptive control algorithms are highlighted. Finally, a comparison of results has been made and the significant improvements obtained with the application of some of these controllers have been exposed

Virtual twin of solar tracker prototype

Máster en Ingeniería Industria

Application of the Unscented Kalman Filter for the Filtering of the Signals in a Remotely Operated Underwater Vehicle

[Resumen] En este documento se presenta la aplicación de la teoría de filtrado Unscented Kalman para el filtrado de las señales de un vehículo subacuático teleoperado(ROV). Para ello, se emplea el modelo no lineal del ROV y se establecen como perturbaciones efectos de las olas de primer orden y ruido de los sensores. Estas perturbaciones se han incorporado a la salida de las señales de los movimientos a controlar. Se emplea el UKF que está especialmente indicado para sistemas no lineales y, por tanto, es adecuado para su implementación en este tipo de vehículos. El modelo utilizado es no lineal con aumento de estados correspondientes a las olas de primer orden. A partir del análisis de los resultados de las simulaciones se puede concluir que el filtro implementado es adecuado y se obtiene una señal de salida de la modelo adecuada para la realimentación al sistema de control.[Abstract] This document presents the application of a Unscented Kalman(UKF) filter for filtering signals from a remotely operated underwater vehicle ( ROV). For this, the nonlinear model of the ROV is used and are set as disturbances the first-order wave effects and noise from sensors. These disturbances have been incorporated at the output of the signals of the movements to be controlled. The UKF is used, which is specially indicated for nonlinear systems and, therefore, it is suitable for implementation in this type of vehicles. The model used is non-linear with increasing of states corresponding to the waves of first order. From the analysis of the results from the simulations it can be concluded that the implemented filter is adequate and the output signal of the model is suitable for feedback on to the control system.https://doi.org/10.17979/spudc.978849749841

Parameter Estimation of a Nonlinear Maneuvering Model of a Remote Operated Vehicle on Basin Trials

[Resumen] En este trabajo, se aplican técnicas de inferencia indirecta para la estimación de parámetros de un modelo de maniobra no lineal de un vehículo subacuático teleoperado (ROV). Para ello, se dispone de datos de diferentes ensayos, que se llevaron a cabo con el citado ROV en las instalaciones del Canal de Experiencias Hidrodinámicas del Pardo CEHIPAR, Madrid. El modelo obtenido se valida mediante métodos gráficos y estadísticos y las propiedades estadísticas de los parámetros estimados se evalúan mediante un estudio de Monte Carlo.[Abstract] In this work, indirect inference techniques are applied to estimate the parameters of a nonlinear maneuvering model of a remote operated vehicle (ROV). For this purpose, data from different tests are available, which were carried out with the ROV in the facilities of the Canal de Experiencias Hidrodinámicas del Pardo CEHIPAR, Madrid. The model obtained is validated by means of graphical and statistical methods and the statistical properties of the estimated parameters are evaluated by means of a Monte Carlo study.Gobierno de Cantabria; VP45Este proyecto ha sido financiado por la Consejería de Universidades, Igualdad, Cultura y Deporte del Gobierno de Cantabria a través del proyecto ControlFond (Control de Vehículos Subacuáticos No Tripulados para Supervisión de Estructuras para Obras Marítimas Fondeadas). (Code: VP45).https://doi.org/10.17979/spudc.978849749804

Gain scheduling model predictive control for dynamic positioning of floating caissons at different draughts

This article presents a model predictive control for dynamic positioning (DP) of floating caisson at different draughts. This article focuses on the maneuvres related to the control of the spatial situation of the caisson in connexion with the final caisson reference point and the process of descending to the seabed desired location. Different models of the caisson in order to perform realistic simulations and to test the robustness of the controller are considered. A gain scheduling model predictive control (GSMPC) has been implemented, with parameter switch among four model predictive control (MPC) controllers. In this way, a specific MPC for the dynamics of each draught will be used in each caisson model corresponding to a draught. Furthermore, a Kalman filter has been implemented to remove the disturbances. Finally, in the simulations results it is compared the performance of the proposed controller with a clasic one and also it is checked how the proposed controller is able to position the system in all draughts with stability and accurate dynamic control of the system.The Spanish FEDER/Ministry of Science, Innovation and Universities–State Research Agency has partially supported through the SAFE Project (Desarrollo de un Sistema Autónomo para el Fondeo de Estructuras para Obras Marítimas), Grant Agreement: Proyecto RTC-2017-6603-4 financiado por MCIN/AEI/10.13039/501100011033 y FEDER “Una manera de hacer Europa”. The Regional Ministry of Universities, Equality, Culture and Sports of the Government of Cantabria has provided partial support through the ControlFond project (Control De Vehículos Subacuáticos No Tripulados Para Supervisión De Estructuras Para Obras Marítimas Fondeadas). The authors would like to thank FCC Construcción S.A. as a collaborator in the development of the SAFE Project, specially Victor Florez Casillas and Nuria Cotallo Aguado (Technical Direction/Hydraulic and Maritime Works) and Alvaro de Toro Mingo (Machinery Direction). Raul Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities. Ayuda RYC-2017- 23260 financiada por MCIN/AEI/10.13039/501100011033 y FSE “El FSE invierte en tu futuro”