Visual perception for the 3D recognition of geometric pieces in robotic manipulation

During grasping and intelligent robotic manipulation tasks, the camera position relative to the scene changes dramatically because the robot is moving to adapt its path and correctly grasp objects. This is because the camera is mounted at the robot effector. For this reason, in this type of environment, a visual recognition system must be implemented to recognize and “automatically and autonomously” obtain the positions of objects in the scene. Furthermore, in industrial environments, all objects that are manipulated by robots are made of the same material and cannot be differentiated by features such as texture or color. In this work, first, a study and analysis of 3D recognition descriptors has been completed for application in these environments. Second, a visual recognition system designed from specific distributed client-server architecture has been proposed to be applied in the recognition process of industrial objects without these appearance features. Our system has been implemented to overcome problems of recognition when the objects can only be recognized by geometric shape and the simplicity of shapes could create ambiguity. Finally, some real tests are performed and illustrated to verify the satisfactory performance of the proposed system.

SQL Server Management Studio Express Instalación

Instalación de SQL Server Management Studio Express en un MS Windows 7 Profesional.

SQL Server Management Studio Express 01

Primeros pasos en el uso de este programa cliente de acceso y administración de SQL Server. Este cliente, en su versión Express, es gratuito. El ejemplo del vídeo se conecta con un servidor remoto SQL Server 2008 R2.

SQL Server Management Studio Express 02

Segunda parte de los primeros pasos en el uso de este programa cliente de acceso y administración de SQL Server. Este cliente, en su versión Express, es gratuito. El ejemplo del vídeo se conecta con un servidor remoto SQL Server 2008 R2. Modificar tablas. Exportar definiciones del esquema. Resultados a cuadrícula o texto. Guardar resultados.

Transacciones en SQL Server

Una introducción a los objetivos y contenidos de la sesión 2 del curso de Bases de Datos dentro del Máster Universitario en Desarrollo de Aplicaciones y Servicios Web de la Universidad de Alicante. Se describe someramente qué se entiende por una transacción y se nombran los niveles de aislamiento en SQL Server. Todo enfocado a la realización de los ejercicios-demostraciones de esos niveles de aislamiento. Ingenuo y con fallos de encuadre e iluminación clamorosos, pero no tiene más ambiciones que la de dejar constancia de algunas de las cosas que se dijeron en clase.

Ejemplos de transacciones en SQL Server

Descripción de cómo facilitar la ejecución de los ejercicios de la sesión de transacciones del moodle de la asignatura. Se trata de reorganizar las ventanas y hacer espacio para tener dos consultas a la vista. En cada una de ellas se mantendrán una o varias transacciones que pretendemos ejecutar simultáneamente. De esta forma podremos ver qué transacciones esperan a las otras y pasar de una a otra consulta con facilidad.

Paginación en SQL Server

Una introducción a los objetivos y contenidos de la sesión 3 del curso de Bases de Datos dentro del Máster Universitario en Desarrollo de Aplicaciones y Servicios Web de la Universidad de Alicante. El trabajo que permite la calificación de esta primera parte del curso se basa, precisamente, en lo que se describe en este vídeo. La paginación de resultados es una técnica que pretende agilizar el manejo remoto de grandes cantidades de datos. El ejemplo clásico es la navegación por un catálogo de productos. Si es el servidor el que, por el procedimiento que sea, divide la lista completa en páginas y solo envía una de ellas al cliente, estamos ahorrando en tiempo y uso de red. En SQL Server, para esta tarea, es fácil encontrar opiniones que desaconsejan el uso de cursores puesto que se supone que el entorno objetivo es de alta concurrencia. No obstante, se puede usar TOP() y ROW_NUMBER(). La sesión consiste en una serie de ejemplos sobre todas estas herramientas.

A Comparative Study of Registration Methods for RGB-D Video of Static Scenes

The use of RGB-D sensors for mapping and recognition tasks in robotics or, in general, for virtual reconstruction has increased in recent years. The key aspect of these kinds of sensors is that they provide both depth and color information using the same device. In this paper, we present a comparative analysis of the most important methods used in the literature for the registration of subsequent RGB-D video frames in static scenarios. The analysis begins by explaining the characteristics of the registration problem, dividing it into two representative applications: scene modeling and object reconstruction. Then, a detailed experimentation is carried out to determine the behavior of the different methods depending on the application. For both applications, we used standard datasets and a new one built for object reconstruction.

A high-resolution binocular video-oculography system: assessment of pupillary light reflex and detection of an early incomplete blink and an upward eye movement

Background: The pupillary light reflex characterizes the direct and consensual response of the eye to the perceived brightness of a stimulus. It has been used as indicator of both neurological and optic nerve pathologies. As with other eye reflexes, this reflex constitutes an almost instantaneous movement and is linked to activation of the same midbrain area. The latency of the pupillary light reflex is around 200 ms, although the literature also indicates that the fastest eye reflexes last 20 ms. Therefore, a system with sufficiently high spatial and temporal resolutions is required for accurate assessment. In this study, we analyzed the pupillary light reflex to determine whether any small discrepancy exists between the direct and consensual responses, and to ascertain whether any other eye reflex occurs before the pupillary light reflex. Methods: We constructed a binocular video-oculography system two high-speed cameras that simultaneously focused on both eyes. This was then employed to assess the direct and consensual responses of each eye using our own algorithm based on Circular Hough Transform to detect and track the pupil. Time parameters describing the pupillary light reflex were obtained from the radius time-variation. Eight healthy subjects (4 women, 4 men, aged 24–45) participated in this experiment. Results: Our system, which has a resolution of 15 microns and 4 ms, obtained time parameters describing the pupillary light reflex that were similar to those reported in previous studies, with no significant differences between direct and consensual reflexes. Moreover, it revealed an incomplete reflex blink and an upward eye movement at around 100 ms that may correspond to Bell’s phenomenon. Conclusions: Direct and consensual pupillary responses do not any significant temporal differences. The system and method described here could prove useful for further assessment of pupillary and blink reflexes. The resolution obtained revealed the existence reported here of an early incomplete blink and an upward eye movement.