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11	Real-time Optimal Braking for Marine Vessels with Rotating Thrusters Jónsdóttir, Sigurlaug Rún January 2022 (has links) Collision avoidance is an essential component of autonomous shipping. As ships begin to advance towards autonomy, developing an advisory system is one of the first steps. An advisory system with a strong collision avoidance component can help the crew act more quickly and accurately in dangerous situations. One way to avoid colission is to make the vessel stop as fast as possible. In this work, two scenarios are studied, firstly, stopping along a predefined path, and secondly, stopping within a safe area defined by surrounding obstacles. The first scenario was further worked with to formulate a real-time solution. Movements of a vessel, described in three degrees of freedom with continuous dynamics, were simulated using mathematical models of the forces acting on the ship. Nonlinear optimal control problems were formulated for each scenario and solved numerically using discretization and a direct multiple shooting method. The results for the first problem showed that the vessel could stop without much deviation from the path. Paths with different curvatures were tested, and it was shown that a slightly longer distance was traveled when the curvature of the path was greater. The results for the second problem showed that the vessel stays within the safe area and chooses a relatively straight path as the optimal way of stoping. This results in a shorter distance traveled compared to the solution of the first problem. Two different real-time approaches were formulated, firstly a receding-horizon approach and secondly a lookup-based approach. Both approaches were solved with real-time feasibility, where the receding-horizon approach gave a better solution while lookup-based approach had a shorter computational time. Nonlinear optimization nonlinear optimal control numerical optimal control real-time solution optimal braking receding horizon modeling ship model propeller forces rudder forces direct multiple shooting method discretization Other Mathematics Annan matematik
12	Hardware-in-the-Loop Simulation of Aircraft Actuator Braun, Robert January 2009 (has links) <p>Advanced computer simulations will play a more and more important role in future aircraft development and aeronautic research. Hardware-in-the-loop simulations enable examination of single components without the need of a full-scale model of the system. This project investigates the possibility of conducting hardware-in-the-loop simulations using a hydraulic test rig utilizing modern computer equipment. Controllers and models have been built in Simulink and Hopsan. Most hydraulic and mechanical components used in Hopsan have also been translated from Fortran to C and compiled into shared libraries (.dll). This provides an easy way of importing Hopsan models in LabVIEW, which is used to control the test rig. The results have been compared between Hopsan and LabVIEW, and no major differences in the results could be found. Importing Hopsan components to LabVIEW can potentially enable powerful features not available in Hopsan, such as hardware-in-the-loop simulations, multi-core processing and advanced plotting tools. It does however require fast computer systems to achieve real-time speed. The results of this project can provide interesting starting points in the development of the next generation of Hopsan.</p> Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Rudder Elevator code translation multicore multi-core real-time simulation hydraulics test rig Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Höjdroder Sidoroder kodöversättning multicore multi-core realtid simulering realtidssimulering hydraulik testrig Mechanical engineering Maskinteknik
13	Hardware-in-the-Loop Simulation of Aircraft Actuator Braun, Robert January 2009 (has links) Advanced computer simulations will play a more and more important role in future aircraft development and aeronautic research. Hardware-in-the-loop simulations enable examination of single components without the need of a full-scale model of the system. This project investigates the possibility of conducting hardware-in-the-loop simulations using a hydraulic test rig utilizing modern computer equipment. Controllers and models have been built in Simulink and Hopsan. Most hydraulic and mechanical components used in Hopsan have also been translated from Fortran to C and compiled into shared libraries (.dll). This provides an easy way of importing Hopsan models in LabVIEW, which is used to control the test rig. The results have been compared between Hopsan and LabVIEW, and no major differences in the results could be found. Importing Hopsan components to LabVIEW can potentially enable powerful features not available in Hopsan, such as hardware-in-the-loop simulations, multi-core processing and advanced plotting tools. It does however require fast computer systems to achieve real-time speed. The results of this project can provide interesting starting points in the development of the next generation of Hopsan. Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Rudder Elevator code translation multicore multi-core real-time simulation hydraulics test rig Hardware-in-the-loop HWiL Hopsan LabVIEW Saab 2000 Ironbird Fortran Höjdroder Sidoroder kodöversättning multicore multi-core realtid simulering realtidssimulering hydraulik testrig Mechanical engineering Maskinteknik

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