Antonio C. Domínguez-Brito

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.

Integrating robotics software

Developing software for controlling robotic systems is costly due to the complexity inherent in these systems. There is a need for tools that permit a reduction in the programming efforts, aiming at the generation of modular and robust applications, and promoting software reuse. The techniques which are of common use today in other areas are not adequate to deal with the complexity associated with these systems. In this work we present CoolBOT, a component oriented framework for programming robotic systems, based on the Port Automata model that fosters controllability and observability of software components. A simple demonstrator outlines the benefits of using the proposed approach in the development of a robotic application.

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.

CoolBOT: A Component-Oriented Programming Framework for Robotics

This paper introduces at the specification level CoolBOT, a component-oriented programming framework for robotics designed to assist robotic system developers in obtaining more structured and reusable systems without imposing any specific architecture. Within this framework components are conceived as Port Automata (PA)[13] that interact through their ports and that can be composed to build up new components from existing ones. Components, no matter if they are atomic or compound, are internally modeled as Discrete Event Systems and controlled using the same state control graph. CoolBOT hides the programmer any aspects related to communications and provides standard mechanisms for different modes of data exchange between components, exception handling and support for distributed computing environments.

An Embedded Low-Power Control System for Autonomous Sailboats

This work presents a small and affordable autonomous sailboat platform designed to be transported and operated by one or two people without any special means. The sailboat is based on a RC One Meter class vessel equipped with a low power 8-bit microcontroller board and a set of navigation sensors (compass, GPS, wind vane, ...) and a 868 MHz RF module. It has been designed to serve as a low cost replicable testbed platform for research in autonomous sailing. The embedded control system makes the sailboat completely autonomous to sail a route determined as a sequence of waypoints, adapting its sailing point dynamically to wind conditions. The control system is completed with an off-board base station that permits to monitor and control the boat or defining a new route. The system is characterized by its long autonomy and robustness in case of communication failures.

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.

CoolBOT: A Component Model and Software Infrastructure for Robotics

In general, we face recurrently some common problems when programming robotic systems: multithreading and multiprocessing, distributed computing, hardware abstraction, hardware and software integration, multiple levels of abstraction and control, the development of a programming tool for a group of users which may become wide and diverse, etc. In this document we will introduce CoolBOT, a component oriented programming framework implementing primitives and mechanisms aimed to support the resolution of some of these common problems. This framework allows building systems by integrating “off-the-shelf” software components following a port automata model [SVK97] that fosters controllability and observability. Next section, Section 2, will introduce some of the recurrent problems we can find when developing the software infrastructure aimed to control a robotic system. In Section 3 we introduce a component oriented programming framework for programming robotic systems called CoolBOT which is the main subject of this chapter. In Section 4 we will outline the use of CoolBOT for building a real example. Finally in Section 5 we outline some of the conclusions we have drawn along the way of building and using CoolBOT.

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.

A-TIRMA G2: An Oceanic Autonomous Sailboat

This paper describes a new design of a 2 meter LOA (Length Over All) autonomous sailboat conceived for sailing in an ample set of weather conditions. The design has been focused on robustness and on achieving some degree of redundancy on critical components like sails and rudder. Accordingly, it is equipped with two light-weight carbon fiber wing sails and two slanted rudders protected by skegs. Its stability curve is fully positive, so she is capable of recovering autonomously from capsizing.