153 research outputs found
Sistema de gobierno automático de accionamiento variable de timones de buques
El invento consiste en un sistema automático de accionamiento variable de timones, cuya caracterĂstica fundamental es que permite variar los rangos del caleje del timĂłn. Los sistemas de gobierno propuestos hasta ahora mueven uno, o más timones, con la propiedad comĂşn a todos ellos de girar dentro de unos lĂmites establecidos de forma fija para todas las situaciones, tales como emergencia, manual, navegaciĂłn, maniobra, piloto automático.Solicitud: 9401778 (27.07.1994)NÂş Pub. de Solicitud: ES2119596A1 (01.10.1998)NÂş de Patente: ES2119596B1 (01.05.1999
Application of a robust QFT linear control method to the course changing manoeuvring of a ship
This paper describes in detail the design methodology of a robust QFT (Quantitative Feedback Theory) controller for the control of the course changing of a ship. A linear model is used with uncertainty in the parameters. The system is designed to fulfil the specifications of robust stability and robust tracking of a reference system
EstimaciĂłn eficiente de parámetros y control en base a un sistema de guĂa LOS modificado de un vehĂculo subacuático
In this work, a methodology is proposed for the improvement of the parameter estimation effciency of a non-linear manoeuvring model of a torpedo shaped unmanned underwater vehicle. For this purpose, data from different tests, were carried out with the aforementioned vehicle at the facilities of the Canal de Experiencias Hidrodinámicas del Pardo, Madrid. In the proposed methodology, the following aspects are taken into account in order to improve the parameter estimation effciency: selection of the sampling period, smoothing of the data acquired in the tests considering a compromise between variance and bias of the smoothing filter to be applied, analysis of the classical linear regression model proposed in each trial, from the statistical point of view for the estimation of the parameters. Improvements in effciency are verified by graphical and statistical methods. In addition, a modification of the conventional LOS method is proposed which provides satisfactory results in the presence of ocean currents by performing a simple procedure
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 AutĂłnomo para el Fondeo de Estructuras para Obras MarĂtimas), 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-hĂculos Subacuáticos No Tripulados Para SupervisiĂłn De Estructuras Para Obras MarĂtimas Fondeadas). The authors would like to thank FCC ConstrucciĂłn 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
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 AutĂłnomo para el Fondeo de Estructuras para Obras MarĂtimas), 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
Hybrid control architecture for navigation of unmanned underwater vehicles
In the present paper, a hybrid architecture based on multi-agent systems is proposed based on a layered system. This architecture presents qualities of modularity and scalability. It is also developed a methodology for trajectory tracking based on the generation of a reliable virtual space, on which the navigation takes place under operative conditions (safety and e ectiveness). Time processing operations reduction is expected during the inspection
Lack of association of vitamin D receptor BsmI gene polymorphism with bone mineral density in Spanish postmenopausal women
La osteoporosis es un trastorno poligĂ©nico que está determinada por los efectos de varios genes, cada uno con efectos relativamente modestos en la masa Ăłsea. El objetivo de este estudio es determinar si el receptor de la vitamina D, Ăşnico nucleĂłtido polimorfismo BsmI, está asociado con la densidad mineral Ăłsea (DMO) de mujeres posmenopáusicas españolas. Un total de 210 mujeres posmenopáusicas sanas, mayores de 60 ± 8 años, fueron genotipificadas utilizando ensayos de genotipado SNP TaqMan® lumbar y la DMO femoral; y se determinĂł por la absorciometrĂa de rayos X de energĂa dual (DEXA) la cantidad diaria de calcio y vitamina D. No se encontraron diferencias en el cuello femoral, trocánter, triángulo de salas, L2, L3, L4, L2-L4, o entre el cuello femoral y la DMO de cadera total tras el ajuste para posibles factores de confusiĂłn (P > 0,05) (edad, IMC, años despuĂ©s de la menopausia y la ingesta diaria de calcio). La BsmI polimorfismo en el gen VDR no se asociĂł con la DMO en mujeres posmenopáusicas españolas.Osteoporosis is a polygenic disorder that is determined by the effects of several genes, each with relatively modest effects on bone mass. The aim of this study was to determine whether the vitamin D receptor single nucleotide polymorphism BsmI is associated with bone mineral density (BMD) in Spanish postmenopausal women. A total of 210 unrelated healthy postmenopausal women aged 60 ± 8 years were genotyped using TaqManR SNP Genotyping Assays. Lumbar and femoral BMD were determined by dual-energy X-ray absorptiometry (DEXA). Daily calcium and vitamin D intake were determined by a food questionnaire. No differences were found in the femoral neck, trochanter, Ward’s Triangle, L2, L3, L4, L2-L4, or between the femoral neck and total hip BMD after further adjustment for potential confounding factors (P > 0.05) (age, BMI, years since menopause and daily calcium intake). The BsmI polymorphism in the VDR gene was not associated with BMD in Spanish postmenopausal women.peerReviewe
Software de procesado de imágenes procedentes de un sonar de barrido lateral en exploración submarina
Digital images provided by onboard sidescan sonar in an unmanned undersea vehicle (UUV), are usually poor in their resolution. There are two commercial expensive solutions for this trouble: the first one is the use of high resolution multibeam sidescan sonar, the second one consists in the use of bathymetric sonar. It is evident that for spanish university these solutions exceeds the economical budget and needs a generous external support. This work shows an economical solution for this problem by using digital image processing techniques under MATLAB environment. Results are comparable in quality with the commercial expensive hardware solutions. The application presented here is easy to use and has been developed under “user friendly” philosophy and could be operated for users at any level. This work is the first step for future lines of work in underwater recognition of objects
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