Diseño del sistema de control para navegación autónoma de un vehículo submarino ligero

El presente Trabajo Final de Master realiza un estudio de distintas implementaciones de control en vehículos submarinos que operan con el firmware de Ardupilot, indicando las características y capacidades presentes en dicho software. Con este objetivo se ha diseñado un sistema apoyado por USBL que permite utilizar el ROV Sibiu Nano + de la empresa Nido Robotics como AUV utilizando un sistema supervisable de puntos de interés indicados por un usuario en tierra. Por último, se evalúan los desempeños de los distintos sistemas de control mediante la realización de pruebas en un ambiente controlado.This project analyses the implementation of different control systems in lightweight underwater vehicles operating with the firmware Ardupilot, making a complete description of their charasteristics and different capabilities. A software aided by USBL has been designed to use the ROV Sibiu Nano + made by Nido Robotics as an AUV using a supervised system of waypoints indicated by an user in the Base Station. Lastly the behaviour of each designed control system will be evaluated via real tests in a controlled environment.Universidad de Sevilla. Máster en Ingeniería en Electrónica, Robótica y Automátic

Modelado, simulación y control de un vehículo submarino ligero

El presente Trabajo Final de Grado realiza un estudio de las leyes que gobiernan el movimiento de vehículos submarinos indicando las magnitudes físicas necesarias para la descripción de un modelo, analizando los grados de actuación disponibles, así como los métodos de percepción, sensores y estrategias de control más utilizadas. Se realizará un estudio del submarino ligero Sibiu Nano Plus de la empresa Nido Robotics, describiendo sus componentes y estimando sus características físicas. Por último, mediante ROS, se diseñará un sistema de control basado en PID y se evaluará su desempeño utilizando el simulador UUVSim.This project analyses the general characteristics of marine vehicles, making a description of the laws that govern movement of marine vehicles looking into the physical magnitudes needed for a complete description of a model and analyzing the available actuation degrees as well as the most used sensors, perception methods and control systems. It will make a study of the light ROV Sibiu Nano Plus from Nido Robotics, describing all its components and making an estimation of its physical characteristics. Lastly, via ROS, there will be an evaluation of the performance of a designed control system using the UUV Simulator.Universidad de Sevilla. Grado en Ingeniería Electrónica, Robótica y Mecatrónic

Performance Analysis of Hybrid Optical–Acoustic AUV Swarms for Marine Monitoring

Autonomous Underwater Vehicles (AUVs) are assuming an important role in the monitoring and mapping of marine ecosystems, especially for their ability to explore harsh environments. AUV swarm can collect data operating autonomously for long periods enabling new applications in this field. However, the mission duration is usually limited also by the high power consumption required for acoustic transmissions. A new generation of devices complements the acoustic modem with an optical modem that can provide a communication channel with higher capacity and lower power consumption with respect to the acoustic channel. However, the optical link that uses the visible light is very sensitive to the water turbidity that can strongly limit the link coverage. In this paper, we evaluate the networking performances of the Venus vessel, a real AUV prototype equipped with an acoustical modem and an optical modem. The presented analysis aims to evaluate key system parameters allowing to select the best way to set up network communications according to the surrounding conditions (e.g., quality of water) and to the application requirements. Simulation results account for the case of ports or basins, where the water quality is poor and the use of the optical modem is strongly limited by distance. We evaluate system performance in terms of transmission delay in the network and we also provide a power–capacity trade-off

Search and restore: a study of cooperative multi-robot systems

Swarm intelligence is the study of natural biological systems with the ability to transform simple local interactions into complex global behaviours. Swarm robotics takes these principles and applies them to multi-robot systems with the aim of achieving the same level of complex behaviour which can result in more robust, scalable and flexible robotic solutions than singular robot systems. This research concerns how cooperative multi-robot systems can be utilised to solve real world challenges and outperform existing techniques. The majority of this research is focused around an emergency ship hull repair scenario where a ship has taken damage and sea water is flowing into the hull, decreasing the stability of the ship. A bespoke team of simulated robots using novel algorithms enable the robots to perform a coordinated ship hull inspection, allowing the robots to locate the damage faster than a similarly sized uncoordinated team of robots. Following this investigation, a method is presented by which the same team of robots can use self-assembly to form a structure, using their own bodies as material, to cover and repair the hole in the ship hull, halting the ingress of sea water. The results from a collaborative nature-inspired scenario are also presented in which a swarm of simple robots are tasked with foraging within an initially unexplored bounded arena. Many of the behaviours implemented in swarm robotics are inspired by biological swarms including their goals such as optimal distribution within environments. In this scenario, there are multiple items of varying quality which can be collected from different sources in the area to be returned to a central depot. The aim of this study is to imbue the robot swarm with a behaviour that will allow them to achieve the most optimal foraging strategy similar to those observed in more complex biological systems such as ants. The author’s main contribution to this study is the implementation of an obstacle avoidance behaviour which allows the swarm of robots to behave more similarly to systems of higher complexity