A review of sensor fusion techniques for underwater vehicle navigation

This work provides a general description of the multi sensor data fusion concept, along with a new classification of currently used sensor fusion techniques for unmanned underwater vehicles (UUV). Unlike previous proposals that focus the classification on the sensors involved in the fusion, we propose a synthetic approach that is focused on the techniques involved in the fusion and their applications in UUV navigation. We believe that our approach is better oriented towards the development of sensor fusion systems, since a sensor fusion architecture should be first of all focused on its goals and then on the fused sensors

Accuracy estimation of a new omnidirectional 3D vision sensor

We present a computer vision system that associates omnidirectional vision with structured light with the aim of obtaining depth information for a 360 degrees field of view. The approach proposed in this article combines an omnidirectional camera with a panoramic laser projector. The article shows how the sensor is modelled and its accuracy is proved by means of experimental results. The proposed sensor provides useful information for robot navigation applications, pipe inspection, 3D scene modelling etc

Calibration of a Structured Light-Based Stereo Catadioptric Sensor

Catadioptric sensors are combinations of mirrors and lenses made in order to obtain a wide field of view. In this paper we propose a new sensor that has omnidirectional viewing ability and it also provides depth information about the nearby surrounding. The sensor is based on a conventional camera coupled with a laser emitter and two hyperbolic mirrors. Mathematical formulation and precise specifications of the intrinsic and extrinsic parameters of the sensor are discussed. Our approach overcomes limitations of the existing omni-directional sensors and eventually leads to reduced costs of production

The project of land restitution in Colombia: an illustration of the civilizing force of hypocrisy?

This article offers a theoretical interpretation of the dispositions on land restitution contained in the famous “Victims’ Bill”, which was debated in the Colombian Congress during the year 2008. The bill included specific mechanisms aimed at guaranteeing the restitution of land to victims of the Colombian armed conflict. At the time, the bill was endorsed by all the main political actors in the country –notably the government and the elites that support it, on the one hand, and victims’ and human rights organizations and other opposition groups, on the other–. The fact that the restitution of land to victims of the Colombian armed conflict was being considered as a serious possibility by all political actors in the country seemed to indicate the existence of a consensus among actors whose positions are ordinarily opposed, on an issue that has traditionally led to high levels of polarization. This consensus is quite puzzling, because it seems to be at odds with the interests and/or the conceptions of justice advocated by these political actors, and because the restitution of land faces enormous difficulties both from a factual and a normative point of view, which indicates that it may not necessarily be the best alternative for dealing with the issue of land distribution in Colombia. This article offers an interpretation of said consensus, arguing that it is only an apparent consensus in which the actors are actually misrepresenting their interests and conceptions of justice, while at the same time adopting divergent strategies of implementation aimed at fulfilling their true interests. Nevertheless, the article concludes that the common adherence by all actors to the principle of restorative justice might bring about its actual realization, and thus produce an outcome that, in spite (and perhaps even because) of being unintended, might substantively contribute to solving the problem of unequal land distribution in Colombia. Even though the article focuses in some detail on the specificities of the 2008 Bill, it attempts to make a general argument about the state of the discussion on how to deal with the issue of land distribution in the country. Consequently, it may still be relevant today, especially considering that a new Bill on land restitution is currently being discussed in Congress, which includes the same restitution goals as the Victims’ Bill and many of its procedural and substantive details, and which therefore seems to reflect a similar consensus to the one analyzed in the article.

Force and movement.

Es una introducción al mundo científico para los niños, con un texto sencillo y con actividades descritas paso a paso. Así, descubren que la ciencia es divertida de aprender y de interés para su vida cotidiana. Este volumen trata de los distintos tipos de fuerzas existentes para poner las cosas en movimiento: empujar, arrastrar, frenar; está dividido en cuatro secciones, cada una de ellas señalada con un triágulo de distinto color en la esquina de la página.

Can you feel the force?

Ofrece información, experiencias, preguntas y respuestas acerca de la física. En primer lugar se presenta una reseña histórica para ayudar a los estudiantes en la comprensión de la materia. En puedes sentir la fuerza, se definen algunos términos y explican las leyes de Newton. En cuál es el problema, explora imanes, y los estados de la materia, y en puede ver la luz analiza la teoría de partículas, el color, rayos electromagnéticos, y la velocidad de la luz. Hay experimentos que ayudan a explicar la materia, fricción, gravedad, la velocidad, la electricidad, la presión del aire y la presión del agua. En la sección quién es quién están los perfiles de 16 científicos, de Aristóteles a Dirac ,y sus descubrimientos. Hay un glosario.

Integració d'un sensor sonar d'escombrat lateral en un robot submarí

El grup de Visió per Computador i Robòtica (VICOROB) disposa de varis robots submarins per a la recerca i inspecció subaquàtica. Recentment s’ha adquirit un sensor sonar d’escombrat lateral el qual s’utilitza per realitzar imatges acústiques del fons marí quan aquest es mou principalment a velocitat constant i mantenint el rumb. Els robots del grup VICOROB estan equipats amb diferents tipus de sensors i càmeres per analitzar el fons marí. Aquest sensors són de gran qualitat i permeten conèixer de manera bastant satisfactòria l’entorn a les proximitats del robot. Freqüentment però, aquest sensors estant sotmesos a diferents restriccions depenent de la seva naturalesa de funcionament, de tal manera que es necessària la seva combinació per resoldre determinats problemes en diferents situacions. Amb aquest projecte, es pretén integrar un nou sistema de captura d’imatges sonores del fons marí, en un dels robots. Amb la integració d’aquest nou sensor, s’espera obtenir una opció alternativa els sistemes actuals que pugui aportar informació addicional sobre el fons. Aquest sistema podrà ser utilitzat per realitzar tasques per les quals els altres sensors no estant preparats o bé per complementar informació d’altres sensor