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Robo-Yacht: a human behaviour-based tool to predict the performances of yacht-crew systems
Full text linkMany numerical tools are available in the yacht design domain to predict yacht performances. These are based on experimental data and well-established numerical techniques. However, being competitive sailing an uncertainty-rich discipline, there is also a need to assess the performances of a yacht’s crew. This is indeed the main area for performance gains. The present study aims at predicting the performances of yacht-crew systems, by including numerical models for human behaviour within those referred to the yacht dynamics.
In particular, the problem of decision-making under weather uncertainty is formulated in terms of a game of chance having nature as a second player and involving risk. Within this context, it is shown that decisionmaking models often used in management sciences can be advantageously used. This approach has led to the development of a sailing simulator referred to as ‘Robo-Yacht’, based on the International America’s Cup Class. A case study is investigated that involves three strategical alternatives and four possible weather scenarios: gains and losses are assessed through the simulator and a formula to express expected payoffs is derived. When different attitudes towards risk (neutral, risk-averse and risk-taking) are expressed as different utility functions,
it is shown that sailors’ choices can be conveniently modeled based on a maximization of expected utility. The ‘automatic crew’ can actually make decisions that appear to be consistent with widely accepted principles of race strategy. A risk function is also derived in order to take into account opponents’ choices and, where necessary, modify the strategic plan accordingly
Kinematics of the 3-CPU parallel manipulator assembled for motions of pure translation
No full textThe paper describes the architecture of a novel parallel kinematics machine that is characterized by motions of pure translation. It is shown that the Cartesian arrangement of the 3 limbs assures simple kinematic relations and an Isotropic workspace, without any rotation or translation singularity. Such good features should allow the design of parallel robots that are characterized by simple controllers and good performances, as an alternative to current mechanical schemes
Including human performance in the dynamic model of a sailing yacht: a matlab-simulink based tool
No full textA sailing simulator is described that takes into account human factors with respect to strategic decisions during a race. Models for yacht-crew interaction have been designed and implemented for the helmsman and the sail tailers, as well as a ‘routing engine’ that solves problems of a strategical and a tactical nature (e.g. navigation in windshifts, collision avoidance). One or more users can interact with the simulator, so that their behaviour and decision-making process can be recorded, analyzed and compared to that of the automatic crews. The software was implemented in MATLAB-Simulink and consists of two modules: ‘Robo-Yacht’, for solo and drag races, and ‘Robo-Race’ for fleet regattas. In the latter case, a real-time animation of the race is delivered to the user in real-time within a virtual reality environment. A series of case studies are presented that demonstrate realistic interactions between a yacht whose decisions are made by a sailor and a mini fleet of autonomous yachts
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mini 6.50 Mast optimisation using a design of experiment approach and finite element analysis simulations
No full textInteractions between yacht-crew systems and racing scenarios combining behavioral models with VPPs
No full textConsiderable progress has been made in the development of Velocity Prediction Programs (VPPs) suitable for analysis of racing yacht performance. Similarly, there has been rapid advances in sensor capabilities (smaller mass, lower power consumption, and greater accuracy) and with a resultant increase in use in helping assess and improve racing yacht performance. While these tools and techniques will no doubt be further refined and computations speeded up, there is also a need to assess the performance of the yacht’s helm and crew. The scope of the present study is the prediction of the performances of a yacht-crew system as a whole, by deriving numerical models for human behaviour alongside with those referred to the physics of yacht motion. The latter issue, the mechanical side of the problem, is analysed by solving yacht equations of motions in the time domain; crew inputs in terms of yacht steering and sail trim are considered. The yacht-crew system can sail a racecourse in an arbitrary wind pattern, according to strategic rules and given decision making schemata
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