The purpose of the thesis was to explore the possibilities of using a Level-Set method to design a time-optimal path planar of a subject to direction-dependent maximum velocities. A promising application for such a planning approach lies in sailboat navigation planning, because of the dynamic ocean waves, current, wind and the characteristics of a sailboat. In the thesis, we developed an IOS application to simulate such scenario as environment properties with wind, static obstacles and the sailboat mapped into direction-dependent velocities in different locations of the environment.  Considering the wind is the main power for the sailboat, a wind speed generation function was created, based on different locations. The Level-Set method is widely used in image processing because of its various advantages, for instance, the ability to deal with topology change and stability. It also can be applied in path planning, in which the process of the Level-Set method can be considered as a continuous wave front propagating with a speed from the start location. A grid-based map was used to represent the environment. While the wave front was crossing the cell on the grid, a time was recorded for every cell, following the negative gradient direction of such crossing time, and then an optimal path could be found. In addition, we used the Narrow Band method to speed up the calculation of processing the level set equation. Finally, this report gives the results of the experiments of static obstacle avoidance, wind effects and smooth path planning.

The advancement of scientific technology and fast economic growth has resulted in the improvement of better living life, especially the island country like Taiwan. It has the embracement of ocean resources and long coastal around island. Thus, people are looking for the quality of leisure life on the island such as sailing for sport, touring and leisure business. This type of leisure tourism is becoming the major trend in cope with the global boating industry. Taiwan started to manufacturing sailboat began in 1980 and has become one of the important sailboat manufacturing countries in the world. Nevertheless, the sailboat use for domestic sport or leisure has been ignored by the government and people due to the discouragement of restrict maritime law enforcement and marine safety upon the coastal water. The lack of clear regulation for embarking the sailboat and ports for the leasing sailboat is another detrimental problem associated with the domestic sailing activities. The lack of integrated law and institution policy has stalled the development of domestic sailing business and activities. The government has imposed the sailboat use under the regulation of touring boat and leisure fishing sport that has resulted in difficulties on providing the leasing place for domestic sailing activities. The present study was initiated to identify the improper regulation, acts and policy introduced by the government and to assess the proper domestic use of sailboat at the coastal fishing port. This is urgent needed especially at the faded and unused fishing ports due to the depletion of near shore fishery resources. The later is considered a major concern in order to finding a measure for retrieving the downward economy at many fishing villages. The research consist of the law, regulations and policy employed by Japan, Hong-Kong, Singapore, Canada, United States, New Zealand and Australia on their conduct regarding the management of sailboat activities and registration. The survey results provides the necessary reference with regard to enforcement law, strategy, policy, institution and integrated management for sailboat activities.

This thesis presents the design of an inertial measurement data acquisition system intended for use in sailboats. The variables of interest are 3-axis acceleration, 3-axis rotation, GPS position/velocity, magnetic compass bearing and wind speed/direction. The design focus is on low-cost micro-electromechanical systems (MEMS) based technology and demonstrating the validity of these technologies in a scientific application. A prototype is constructed and submitted to a series of tests to demonstrate functionality and soundness of the design. These tests range from bench tests to full scale application. Contributions of this thesis include the novel application of inertial measurement unit (IMU) technology to a sailboat racing application, the integration of all instrumentation, creative ruggedised packaging and emphasising the use of low-cost commercial off-the-shelf (COTS) technology.

This thesis presents the design of an inertial measurement data acquisition system intended for use in sailboats. The variables of interest are 3-axis acceleration, 3-axis rotation, GPS position/velocity, magnetic compass bearing and wind speed/direction. The design focus is on low-cost micro-electromechanical systems (MEMS) based technology and demonstrating the validity of these technologies in a scientific application. A prototype is constructed and submitted to a series of tests to demonstrate functionality and soundness of the design. These tests range from bench tests to full scale application. Contributions of this thesis include the novel application of inertial measurement unit (IMU) technology to a sailboat racing application, the integration of all instrumentation, creative ruggedised packaging and emphasising the use of low-cost commercial off-the-shelf (COTS) technology.

Les voiliers autonomes sont des plate-formes de mesure océanographique à fort potentiel, notamment du fait de leur maniabilité, de leurs faibles signatures thermique et acoustique et de leur grande autonomie énergétique. Leur principal handicap est que leur force motrice dépend du vent et de sa nature incontrôlable et partiellement non prévisible. Un voilier est donc un système sous-actionné. Sa capacité à suivre une orientation dépend de sa vitesse d'avancement, elle même résultant de l'action du vent sur ses voiles. Un réglage inadéquat de celles-ci entravera son bon fonctionnement et risquerait de le faire gîter dangereusement. Pour atteindre des coordonnées cibles, la majorité des voiliers assure une vitesse d'avancement non nulle via le réglage de voile et effectue un asservissent de cap en modifiant l'angle du safran. Ce type d'asservissement néglige les effets de dérive dûs aux efforts latéraux sur les voiles. La direction de la route diffère donc de celle du cap, ce qui doit être pris en compte lors de la planification locale du voilier.Enfin, la plupart des voiliers autonomes utilisent des correcteurs distincts pour régler les voiles et le safran. Or, selon les conditions de navigation, de telles commandes découplées peuvent nuire au bon fonctionnement du voilier. Ce travail adresse ces différents problèmes et propose des solutions pour trouver un réglage de voile maximisant la vitesse du voilier tout en assurant son intégrité, asservir la route du voilier et donc simplifier sa planification locale et enfin coordonner les actions des voiles et du safran pour augmenter la maniabilité du voilier quand les conditions de navigation sont défavorables. / Autonomous sailboats constitute promising plateforms for oceanic measurments. This is mainly due to their manoeuvrability, their low thermal and acoustic signatures and their high energetic autonomy. Their main drawback is that the propulsion force of a sailboat depends on the wind that is not controllable and partially unpredictible. Thus, a sailboat is an under-actuated system. Its ability to follow a direction relies on its longitudinal velocity and results from the action of the wind on its sails. An un-appropriated sail trimming may slow down the sailboat and increase its heeling dangerously. On the other side and To reach a waypoint, most autonomous sailboats will trim their sails to ensure a non-null velocity while achieving a heading controller that act on the rudder to change the orientation of the sailboat. Such heading controller neglect the leeway that results from the lateral forces on the sails. Thus, the route of a sailboat is different from its heading and this should be taked into account while doing local planning. Finally, autonomous sailboats mainly use different controllers for trimming the sails and the rudder. But, depending on sailing conditions, such uncoupled controllers may have negative impact on the maneuvrability of the sailboat. This work focuses on these problems and give solutions to find a sail trimming that maximize the velocity of the sailboat while ensuring a safe cruising, to control the route of the sailboat and simplify the local path planning process and to coordinate the actions on the sails and rudder to increase the maneauvrability while cruising conditions are not adequate.

This thesis presents the design of an inertial measurement data acquisition system intended for use in sailboats. The variables of interest are 3-axis acceleration, 3-axis rotation, GPS position/velocity, magnetic compass bearing and wind speed/direction. The design focus is on low-cost micro-electromechanical systems (MEMS) based technology and demonstrating the validity of these technologies in a scientific application. A prototype is constructed and submitted to a series of tests to demonstrate functionality and soundness of the design. These tests range from bench tests to full scale application. Contributions of this thesis include the novel application of inertial measurement unit (IMU) technology to a sailboat racing application, the integration of all instrumentation, creative ruggedised packaging and emphasising the use of low-cost commercial off-the-shelf (COTS) technology.

This thesis aims to help sailboat owners to decide a preferable NACA profile. A CFD comparison in terms of drag and lift coefficients between two NACA profiles have been applied on a typical fin keel. Each profile has been computed with different angles of attack to investigate the impact of small direction changes. ANSYS Fluent 13.0 is used to model the flow according to RANS k-epsilon model. The conclusion is that NACA65 series gives lower drag while NACA64 series gives higher lift. / Syftet med det här examensarbetet är att undersöka skillnaderna för olika NACA-kölprofiler med avseende på tryckkoefficienter Arbetet strävar även efter att ge båtägare en tydligare bild av en fördelaktig NACA-profil. Varje kölprofil har beräknats med olika anfallsvinklar för att undersöka effekten av små vinkeländringar. ANSYS Fluent 13.0 har använts för att modellera flödet enligt k-epsilon-modellen. Slutsatsen är NACA65-serien ger en lägre motståndskoefficient medan NACA64-serien ger en högre lyftkoefficient.

This research provides a detailed and systematic update of the traditional sailboat design process, with specific attention being paid to the tools used for evaluation purposes, and in doing so creates an improved and optimized design process for sailboats. More specifically, this report seeks to modify a systems-engineering approach to the ship design process, in order to properly incorporate modern sailboat evaluation techniques as well as elements of traditional sailboat design while providing analysis of a case study from Virginia Polytechnic Institute and State University's ocean vehicle design class. In considering all intricacies of sailboat design and with applications and gradual improvement in quality of design through the use of multi-objective optimization methods, a new sailboat design process evolves, which initially considers a wide variety of design options and alternatives. Specific attention is paid in this process to the evolution of the ordering and analysis of each segment of the subprocesses, reducing design risk through the use of industry standard assessment procedures and ensuring consistent interaction with the customer. In doing so, an improved and effective design process is established, to be used by future sailboat design teams at Virginia Polytechnic Institute and State University. / Master of Science / Boats and marine vehicles of different types have long been a mainstay in the growth and development of this country's military, economic and transportation infrastructure. Whether being used for fishing purposes in the Pacific Northwest or moving oil and gas to different cities along the eastern seaboard, marine transportation plays a critical role in day to day life. Long before the invention of gasoline powered engines, most boats were powered by wind which was harnessed by the use of sails. In the 1800's sailboats were used extensively for fishing, delivering mail and a number of other important activities. Nowadays, the use of sailboats is more geared towards recreational endeavors including racing or simply cruising local waterways. It is the responsibility of the sailboat designer to deliver options and products commensurate with the prospective owner's preferences. As such, it is important for the designer to develop a process or system which incorporates useful tools which can successfully evaluate design alternatives. In doing so, useful information will be produced by which the owner and designer can collaboratively make decisions. Unlike a military or commercial ship, the owner of a sailboat is most likely the main operator and shares a personal connection with the boat. This study modifies a systems-engineering approach to the ship design process, in order to properly incorporate modern sailboat evaluation techniques as well as elements of traditional sailboat design. In doing so, the operation provides a process and tool benchmark for future sailboat design teams at Virginia Polytechnic Institute and State University.

In this paper, an algorithm that calculates the direction of the wind from the directions of sailors during fleet races is proposed. The algorithm is based on a 1-D spatial convolution and it is named Convolution Based Direction Filtering (CBDF). The CBDF-algorithm is used in the TracTrac race client that broadcasts sailboat races in real-time. The fact that the proposed algorithm is polynomial makes it suitable, to be used as a real-time application inside TracTrac, even for large fleets. More concretely, we show that the time complexity of the CBDF-algorithm is O(n2), in the worst-case, where n > 0 is the number of boats in competition. It is also shown that in more realistic sailing scenarios, the CBDF-algorithm is in fact a linear algorithm.

Sailboat winches are used to help sailors manipulate the control lines that control the position and shape of the sails. Unlike most winches sailboat winches usually only have the ability to winch in the rope, but not to reverse. To reverse the line a sailor needs to manually manipulate it, this is both inconvenient and can also be a safety hazard. This master’s thesis will focus on the development of a self-locking braking system that will be used to allow a sailboat winch to reverse. The goal of the thesis is to design a braking system that works with a modified version of the E40i winch produced by Seldén. The braking system that was developed during this thesis is made up of two main parts, a one-way mechanism and a brake. The type of one-way mechanism that was chosen was an overrunning roller clutch. For the brake a wet disk brake was chosen with an outer diameter of 50mm and an inner diameter of 28.8mm. A 3D model of the braking system has been generated and materials have been selected so that the system is ready for prototyping and physical testing.