Enrique Fernández-Perdomo

Path planning for gliders using Regional Ocean Models: Application of Pinzón path planner with the ESEOAT model and the RU27 trans-Atlantic flight data

Unmanned Underwater Vehicles (UUVs) are commonly used in Oceanography due to their relative low cost and wide range of capabilities. Gliders, being UUVs, are particularly suitable for long-range missions because of their large autonomy. They change their buoyancy to dive and climb describing a vertical saw tooth route, which produces an effective but low horizontal speed. This makes them strongly sensitive to ocean currents, and therefore, they might have to adapt the heading to the current field.

Path planning for underwater gliders using iterative optimization

Underwater gliders constitute a technology in active development, which has proven very promising in Ocean Research because of its relative low cost and long mission range. Due to their low surge speed, however, gliders are strongly affected by ocean currents, making path planning a crucial tool for this type of vehicles. In this work, we present a novel path planning algorithm for gliders based on iterative optimization that shows promising results in realistic simulations. This method reflects accurately the vehicle operation pattern and exhibits a better performance when compared with alternative approaches that are compared in this paper.

Adaptive Bearing Sampling for a Constant-Time Surfacing A* path planning algorithm for gliders

Unmanned Underwater Vehicles (UUVs) are commonly used in Oceanography due to their relative low cost and wide range of capabilities. Gliders are a type of UUV particularly suitable for long-range missions because of their large autonomy. They change their buoyancy to dive and climb describing a vertical saw tooth pattern, which produces an effective but low horizontal speed. Consequently, gliders are strongly sensitive to ocean currents, so they might have to adapt the heading to the current field. In this article we outline a novel path planning algorithm for gliders using ocean currents. It bases on the A* family of algorithms and incorporates a probabilistic framework. Our approach intends to alleviate some of the drawbacks that A* has with the problem at hand. Instead of discretizing the search space, a set of bearing angles is sampled at each surfacing point and the glider trajectory is integrated. We propose an Adaptive Bearing Sampling (ABS) procedure which reduces the computational time with low impact on the results, as shown by the tests run with ocean currents of a Regional Ocean Model.

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.

Optimization-Based Weather Routing for Sailboats

In this paper we propose a deterministic route planner for a sailboat suitable for areas where high quality wind and currents forecasts are available. An optimization based approach is used with the objective of minimizing the time required to arrive at a destination. Several simulations have been performed using high resolution regional forecasts from HIRLAM and MyOcean models in order to test the validity of this method.

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.

Application of iterative-optimization techniques to solve hold track problem in glider navigation

Underwater gliders are vehicles characterized by their persistence as they allow missions extremely long requiring very low power consumption. However, this also implicates that they are much more affected by adverse environmental conditions during navigation, making the use of path planning a crucial tool for this vehicles. In this work we analyse the problem of following a desired trajectory, also known as hold-track navigation. We propose a solution based on optimizations that offers promising results on simulation, both for synthetic and real ocean currents. The scheme is flexible and can be adapted to different sub-problems.