Jorge Cabrera

Glider Path-Planning for Optimal Sampling of Mesoscale Eddies

In the present work we propose a method for generating ocean glider trajectories that optimize the sampling of mesoscale eddy structures based on a given objective function and the predictions available from ROMS maps. The eddy structure is modeled as a 3D volume discretized into sectors rotating around its center at different velocities. The objective functions can then be expressed in terms of those temporal evolving sectors. A set of simulation experiments have been carried out in order to validate the proposal.

Ocean Glider Path Planning Based on Automatic Structure Detection and Tracking

While traditional glider path planning relies on constant model forecasts with only a limited range, a new approach to glider operation is based on automated topographical understanding incorporating feature detection and tracking techniques. Encapsulating the key elements of ocean structure dynamics and focusing on their behaviour an alternative prediction data model can be developed. This feature-based characterization is then used to improve upon the glider path planning. Additionally a structural comparison of ROMs and global models is conducted as well as a forecast assessment within the model. This approach is applied to the case of mesoscale eddies that form around the canary islands and spin off describing various trajectories depending on origin, type and time of the year.

AVORA I Successful Participation in SAUC-E’12

The AVORA team went for the first time to the SAUC-E competition. The AUV was built from scratch with low-cost components. We made watertight cases, as for the servos of a pan-tilt camera aligned with a laser pointer, used for active vision and depth estimation. The navigation and localization use robust algorithms for noisy low-cost sensors. On top of it, the competition tasks are solved with visual and acoustic techniques. A great part of the software was developed and several field test performed at the arena, winning one prize.

Control Action Continuity on Situation-Based Obstacle Avoidance

This work is related to the analysis of reactive obstacle avoidance in general, and specifically to ND algorithms family. Contrary to many previous methods, the ND approach is not aimed at devising a general motion law; instead, it operates over a reduced set of possible situations that are treated by a particular motion law. The big earning of this idea is that it eases the design of control, as now motion laws are specific to every identifiable situation. However, it also raises new issues as nothing guarantees the control action continuity when the diagnostic changes. In this paper a modification of the ND approach, along with experimental results, is presented in order to improve this aspect of the method.A method of controlling a memory device is disclosed wherein the memory device includes a plurality of memory cells. The method comprises providing first block size information to the memory device, wherein the first block size information defines a first amount of data to be output onto a bus in response to a read request. The method further includes issuing a first read request to the memory device, wherein in response to the first read request, the memory device outputs the first amount of data corresponding to the first block size information onto the bus synchronously with respect to an external clock signal. In one preferred embodiment, the method may include providing a code which is representative of a number of clock cycles of the first and second external clock which are to transpire before data is output by the memory device onto the bus. The memory device stores the code in a programmable register on the memory device. In this preferred embodiment, the first amount of data corresponding to the first block size information is output after the number of clock cycles of the external clock transpire.

Sharing Gaze Control in a Robotic System

The use of the vision in humans is a source of inspiration for many research works in robotics. Attention mechanisms has received much of this effort, however, aspects such as gaze control and modular composition of vision capabilities have been much less analyzed. This paper describes the architecture of an active vision system that has been conceived to ease the concurrent utilization of the system by several visual tasks. We describe in detail the functional architecture of the system and provide several solutions to the problem of sharing the visual attention when several visual tasks need to be interleaved. The systems design hides this complexity to client processes that can be designed as if they were exclusive users of the visual system. Besides, software engineering principles for design and integration, often forgotten in this kind of developments, have been considered. Some preliminary results on a real robotic platform are also provided.

MTVS: a multi-task active-vision system

This paper describes the architecture of an active-vision system that has been conceived to ease the concurrent utilization of a visual sensor by several tasks on a mobile robot. We describe in detail the functional architecture of the system and provide several solutions to the problem of sharing the visual attention among multiple visual tasks. The systems design hides this complexity to client processes that can be designed as if they were exclusive users of the visual system. The results obtained in experiments with real mobile robots are also presented.