eVentos 2 - Autonomous sailboat control

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de ComputadoresSailboat navigation started as a way to explore the world. Even though performance is significantly lower than that of a motorboat, in terms of resources, these vessels still are the best low-cost solutions. On the past, navigation depended greatly on estimates or on the stars. Nowadays it depends on precise data provided by a variety of electronic devices, independent from the user’s location. Autonomous sailboats are vessels that use only the wind for propulsion and have the capacity to control its sails and rudders without human intervention. These particularities give them almost unlimited autonomy and a very valuable ability to fulfill long term missions on the sea, such as collecting oceanographic data, search and rescue or surveillance. This dissertation presents a fuzzy logic controller for autonomous sailboats based on a proposed set of sensors, namely a GPS receiver, a weather meter and an electronic compass. Following a basic navigation approach, the proposed set of sensorswas studied in order to obtain an effective group of variables for the controller’s fuzzy sets, and rules for its rule base. In the end, four fuzzy logic controllers were designed, one for the sail(to maximize speed) and three for the rudder (in order to comply with all navigation situations). The result is a sailboat control system capable of operation in a low cost platform such as an Arduino prototyping board. Simulated results obtained from a data set of approximately 100 tests to each controller back up the theory presented for the controller’s operation, since physical experimentation was not possible

Autonomous Sailboat Navigation

The purpose of this study was to investigate novel methods on an unmanned sailing boat, which enables it to sail fully autonomously, navigate safely, and perform long-term missions. The author used robotic sailing boat prototypes for field experiments as his main research method. Two robotic sailing boats have been developed especially for this purpose. A compact software model of a sailing boat's behaviour allowed for further evaluation of routing and obstacle avoidance methods in a computer simulation. The results of real-world experiments and computer simulations are validated against each other. It has been demonstrated that autonomous boat sailing is possible by the effective combination of appropriate new and novel techniques that will allow autonomous sailing boats to create appropriate routes, to react properly on obstacles and to carry out sailing manoeuvres by controlling rudder and sails. Novel methods for weather routing, collision avoidance, and autonomous manoeuvre execution have been proposed and successfully demonstrated. The combination of these techniques in a layered hybrid subsumption architecture make robotic sailing boats a promising tool for many applications, especially in ocean observation

A comparison of non-stationary, type-2 and dual surface fuzzy control

Type-1 fuzzy logic has frequently been used in control systems. However this method is sometimes shown to be too restrictive and unable to adapt in the presence of uncertainty. In this paper we compare type-1 fuzzy control with several other fuzzy approaches under a range of uncertain conditions. Interval type-2 and non-stationary fuzzy controllers are compared, along with ‘dual surface’ type-2 control, named due to utilising both the lower and upper values produced from standard interval type-2 systems. We tune a type-1 controller, then derive the membership functions and footprints of uncertainty from the type-1 system and evaluate them using a simulated autonomous sailing problem with varying amounts of environmental uncertainty. We show that while these more sophisticated controllers can produce better performance than the type-1 controller, this is not guaranteed and that selection of Footprint of Uncertainty (FOU) size has a large effect on this relative performance

Automatic control for autonomous sailing boats

Avtonomne jadrnice so robotska plovila, ki brez potrebe po človekovih posegih uporabljajo veter za pogon in upravljajo z jadri in krmilom. Namen razvoja teh plovil je izdelava jadrnice brez posadke, ki omogoča popolno samostojno jadranje, varno plovbo in izvajanje dolgoročnih nalog na morju. Najpomembnejši sistemi avtonomnih jadrnic so: sistem za dolgoročno načrtovanje plovne poti v odvisnosti od vremenskih razmer, sistem za kratkoročno preusmerjanje jadrnice v odvisnosti od trenutnih podatkov iz senzorjev, sistem za izogibanje trkom in sistem za upravljanja s plovilom. Uporaba mehke (neizrazite) logike pri programiranju nadzornega sistema za upravljanje aktuatorjev se je izkazala za zelo primerno orodje za prenos ekspertnega znanja izkušenih jadralcev v računalniške programe v obliki preprostih pravil vrste ČE-POTEM. Cilj raziskav, predstavljenih v tem delu, je predlog novih nastavitev jader in aktuatorjev ter predlog sistema upravljanja, ki temelji na mehki logiki. Predlagamo razvoj avtonomne jadrnice s tremi različnimi sprednjimi jedri in možnostjo spreminjanja velikosti glavnega jadra. Možnost uporabe več jader v odvisnosti od vetrovnih pogojev in valov na morju podaljšuje obdobje najbolj učinkovitega delovanja (največje hitrosti) jadranja. Zaradi tega jadrnica z omenjeno postavitvijo jader prikazuje bolj realen model, ki se danes uporablja predvsem za oceanskega potovanja. Simulacije jadrnice s tremi različnimi sprednjimi jedri in možnostjo spreminjanja velikosti glavnega jadra so pokazale, da je uporaba mehke logike v nadzornem sistemu, ki upravlja z aktuatorji, smiselna in odpira možnost za razvoj hitrejšega, bolj stabilnega in energetsko učinkovitega plovila.Autonomous sailing boats are robotic vessels that use the wind to drive and can operate the sails and rudder without the need for human intervention. The purpose of the development of these vessels is constructing boats without crew, enabling full independent sailing, safe navigation and implementation of long-term tasks at sea. The most important systems of autonomous sailing boats are: long-term planning waterways, depending on weather conditions, short course routing depending on the current data from sensors, collision avoidance and control system for manoeuver execution. Using fuzzy logic for programming the control system for the management of the actuators, has proven to be a very suitable tool for the transfer of expert knowledge of experienced sailors in computer programs in the form of simple IF-THEN rules. The aim of the research, presented in this work, is to propose a new sails and actuators setting, and a management system based on fuzzy logic. We propose the development of an autonomous sailing boat with three different front sails and the possibility of changing the size of the main sail. The possibility of using different sail settings depending on wind and waves conditions at sea, extends the period of high performance (maximum speed) sailing. An autonomous sailing boat with this sail settings, represents a more realistic model of standard sailing boat used for ocean travel. Simulations of a sailing boat with three different front sails and the possibility of changing the size of the main sail, has shown that the use of fuzzy logic in the control system, that operates the actuators, is meaningful and opens the possibility for the development of faster, more stable and energy-efficient vessels

Design and Development of Industrial Systems for Guidance and Control of Marine Surface Vessels

This paper discusses the design and development of industrial systems for guidance and control of marine surface vessels. In order to cover the large area of industrial marine guidance and control, focus has been given on the relatively high-level physical and logical design issues that dictate system capabilities, justified by a holistic view on GNC (Guidance, Navigation, and Control) systems. This project makes an effort to achieve this goal by structuring and categorizing the industrial systems and relating them to the academic framework found in the academic literature. This paper focuses on industrial methods of GNC and multi sensor monitoring system. Throughout this paper, an effort is made to relate issues, technical and safety wise to international regulations and standards in order to ensure realistic premises. The findings of this project are expected to be useful on developing remotely control self-navigated surface vessel which then could revolutionize the way of deploying and supporting underwater vehicle operation

FASt - An autonomous sailing platform for oceanographic missions

Sailing has been for long times the only means of ship propulsion at sea. Although the performance of a sailing vessel is well below the present power driven ships, either in terms of navigation speed and predictability, wind energy is absolutely renewable, clean and free. Unmanned autonomous sailing boats may exhibit a virtually unlimited autonomy and be able to perform unassisted missions at sea for long periods of time. Promising applications include oceanographic and weather data collecting, surveillance and even military applications. The Microtransat competition, launched in Europe in 2006, has been a key initiative to promote the development of robotic unmanned sailing boats. Various regattas have taken place across Europe and the ultimate challenge will be a transatlantic race. This paper presents an autonomous sailing boat developed at the University of Porto, Portugal, with emphasis on the hardware and software computing infrastructure. This platform is capable of carrying a few kilograms of sensing equipment that can be hooked to the boat's main computer, also providing support for short and long range data communications

Modelling and design of an autonomous sailboat for ocean observation

Includes bibliographical references.This study presents various aspects of the development of an autonomous sailboat for ocean observation, with specific focus on modelling and simulation. The potential value of such platforms for ocean observation is well established, with there being a number of expected advantages over existing solutions. A comprehensive literature review is presented, revealing that the modelling of sailboats is an existing field but that the modelling of small autonomous platforms appears to have been limited. This study develops three and four degree of freedom models of a small autonomous J-Class style sailboat. The sailboat is a prototype platform which is developed from its existing state as part of the study. Both models are validated against data logged during field tests, showing broad agreement with some limitations being noted. Results of simulations of the models are used to draw a number of conclusions regarding the appropriate design of the platform's wing-sail, the wing-sail's control requirements in diffirent wind conditions, potential modifications of the platform's design, and the control of its heading while sailing. Results are also used to inform the proposal of a novel 'variable draft sailing spar' as an alternative autonomous sailboat design

Position keeping control of an autonomous sailboat

International audienceThis paper addresses the problem of reaching and keeping a target position for a sailboat. A method to control sail angle is proposed, using an adaptive adjustment of the sail to regulate the acceleration of the sailboat. A tacking strategy is defined to navigate into the wind, arrive upwind to slow down the boat and then to stay close to the target point. Simulation results show the effectiveness of the proposed approach. The stability of the sailboat using the proposed control has been proven

Navigation and Control of an Autonomous Sailing Model Boat

The purpose of this thesis is to develop navigation and control strategies for an autonomous sailing model boat. Autonomous sailboats are good candidates both for long term oceanic surveys and for patrolling and stealth operations, since they use wind power as their main mean of propulsion which ensures low power requirements, a minimal acoustic signature and a relatively small detectable body. Controlling a sailboat, however, is not an easy task due to high variability in wind, side drift of the boat and challenges encountered when attempting to traverse an upwind course. In this thesis, we describe how we design and set up a control architecture that al- lows Aeolus, an autonomous model sailboat provided by the Swiss Federal Institute of Technology in Zurich, ETH, to sail upwind and execute fast and smooth tacking maneuvers. We implemented different controllers to actuate the rudder in upwind sailing while tacking. We present experimental results obtained during several autonomous sailing tests conducted at Lake Zurich, Switzerland