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Cooperative optimal path planning for herding problemsLu, Zhenyu 15 May 2009 (has links)
In this thesis we study a new type of pursuit-evasion game, which we call the
herding problem. Unlike typical pursuit evasion games where the pursuer aims to
catch or intercept the evader, the goal of the pursuer in this game is to drive the
evader to a certain location or region in the x-y plane. This herding model is proposed
and represented using dynamic equations. The model is implemented in an effort to
understand how two pursuers work cooperatively to drive multiple evaders to the
desired destination following weighted time-optimal and effort-optimal control paths.
Simulation of this herding problem is accomplished through dynamic programming by
utilizing the SNOPT software in the MATLAB environment. The numerical solution
gives us the optimal path for all agents and the corresponding controls as well as the
relative distance and angle variables. The results show that the pursuers can work
cooperatively to drive multiple evaders to the goal.
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Fault Tolerant Message Routing Algorithm on Double-Loop NetworksHuang, Shi-Hang 17 June 2002 (has links)
Message routing is a fundamental function of a network, and fault-tolerance is an important tool to ensure the quality of service of a network. Assume that network contain only one faulty
element. In order to ensure the message can be arrived. We present a fault-tolerant message routing algorithm which being the secondary path, as the optimal path can't be connected in the
double-loop networks.
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Analytical and Numerical Optimal Motion Planning for an Underwater GliderKraus, Robert J. 06 May 2010 (has links)
The use of autonomous underwater vehicles (AUVs) for oceanic observation and research is becoming more common. Underwater gliders are a specific class of AUV that do not use conventional propulsion. Instead they change their buoyancy and center of mass location to control attitude and trajectory. The vehicles spend most of their time in long, steady glides, so even minor improvements in glide range can be magnified over multiple dives.
This dissertation presents a rigid-body dynamic system for a generic vehicle operating in a moving fluid (ocean current or wind). The model is then reduced to apply to underwater gliders. A reduced-order point-mass model is analyzed for optimal gliding in the presence of a current. Different numerical method solutions are compared while attempting to achieve maximum glide range. The result, although approximate, provides good insight into how the vehicles may be operated more effectively.
At the end of each dive, the gliders must change their buoyancy and pitch to transition to a climb. Improper scheduling of the buoyancy and pitch change may cause the vehicle to stall and lose directional stability. Optimal control theory is applied to the buoyancy and angle of attack scheduling of a point-mass model.
A rigid-body model is analyzed on a singular arc steady glide. An analytical solution for the control required to stay on the arc is calculated. The model is linearized to calculate possible perturbation directions while remaining on the arc. The nonlinear model is then propagated in forward and reverse time with the perturbations and analyzed. Lastly, one of the numerical solutions is analyzed using the singular arc equations for verification. This work received support from the Office of Naval Research under Grant Number N00014-08-1-0012. / Ph. D.
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Fraturas e caminhos ?timos na rede de Barabasi-AlbertNunes, Thiago Cris?stomo Carlos 29 June 2012 (has links)
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Previous issue date: 2012-06-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Following the study of Andrade et al. (2009) on regular square lattices, here we investigate the
problem of optimal path cracks (OPC) in Complex Networks. In this problem we associate
to each site a determined energy. The optimum path is defined as the one among all possible
paths that crosses the system which has the minimum cost, namely the sum of the energies
along the path. Once the optimum path is determined, at each step, one blocks its site with
highest energy, and then a new optimal path is calculated. This procedure is repeated until
there is a set of blocked sites forming a macroscopic fracture which connects the opposite
sides of the system. The method is applied to a lattice of size L and the density of removed
sites is computed. As observed in the work by Andrade et al. (2009), the fractured system
studied here also presents different behaviors depending on the level of disorder, namely weak,
moderated and strong disorder intensities. In the regime of weak and moderated disorder,
while the density of removed sites in the system does not depend of the size L in the case of
regular lattices, in the regime of high disorder the density becomes substantially dependent
on L. We did the same type of study for Complex Networks. In this case, each new site is
connected with m previous ones. As in the previous work, we observe that the density of
removed sites presents a similar behavior. Moreover, a new result is obtained, i.e., we analyze
the dependency of the disorder with the attachment parameter m / Seguindo a linha do trabalho de Andrade e colaboradores (2009) em redes regulares, n?s investigamos o problema da fratura atrav?s do caminho ?timo (optimal path cracks -OPC) em Redes Complexas. Neste problema n?s associamos para cada s?tio uma determinada energia. O caminho ?timo ? definido como aquele, dentre todos os poss?veis, que atravessa o sistema e tem o menor custo, ou seja, a menor soma das energias ao longo do caminho. Uma vez que o caminho ?timo ? determinado, em cada passo, n?s bloqueamos o s?tio com maior energia e a partir de ent?o um novo caminho ?timo ? calculado. Este procedimento ? repetido at? que existe um conjunto de s?tios bloqueados que forma uma fratura macrosc?pica a qual conecta lados opostos do sistema. O m?todo ? aplicado numa rede de lado L e a densidade de s?tios removidos ? computada. Como observado no trabalho de Andrade e colaboradores, o sistema fraturado que n?s estudamos tamb?m apresenta diferentes comportamentos dependendo do n?vel da desordem, que pode ser fraca, moderada ou forte. No regime de desordem fraca e moderada, a densidade de s?tios removidos no sistema n?o depende do tamanho L no caso de redes regulares, enquanto no regime de desordem forte a densidade se torna substancialmente dependente de L. N?s fizemos o mesmo tipo de estudo para Redes Complexas. Numa rede complexa caso, cada novo s?tio ? conectado a m s?tios que j? est?o presentes na rede. Como no trabalho anterior, n?s observamos que a densidade de s?tios removidos apresenta um comportamento similar. Al?m disso, um novo resultado ? obtido, isto ?, n?s analisamos a depend?ncia da desordem com o par?metro de liga??o m
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Optimal Path Planning for Single and Multiple Aircraft Using a Reduced Order FormulationTwigg, Shannon 09 April 2007 (has links)
High-flying unmanned reconnaissance and surveillance systems are now being used extensively in the United States military. Current development programs are producing demonstrations of next-generation unmanned flight systems that are designed to perform combat missions. Their use in first-strike combat operations will dictate operations in densely cluttered environments that include unknown obstacles and threats, and will require the use of terrain for masking. The demand for autonomy of operations in such environments dictates the need for advanced trajectory optimization capabilities. In addition, the ability to coordinate the movements of more than one aircraft in the same area is an emerging challenge.
This thesis examines using an analytical reduced order formulation for trajectory generation for minimum time and terrain masking cases. First, pseudo-3D constant velocity equations of motion are used for path planning for a single vehicle. In addition, the inclusion of winds, moving targets and moving threats is considered. Then, this formulation is increased to using 3D equations of motion, both with a constant velocity and with a simplified varying velocity model. Next, the constant velocity equations of motion are expanded to include the simultaneous path planning of an unspecified number of vehicles, for both aircraft avoidance situations and formation flight cases.
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Identify the driving behaviour in a parking lot in terms of distance.Ahmed, Salim Saif Saeed January 2018 (has links)
Parking a vehicle can often lead to frustration, air pollution and congestion due to limited availability of parking spaces. With increasing population density this problem can certainly increase unless addressed. Parking lots occupy large areas of scarce land resource therefore it is necessary to identify the driving behaviour in a parking lot to improve it further. This Paper tries study the driving behaviour in the parking lot and for this endeavours it conducted direct observation in three parking lots and used GPS data that was collected prior to this study by the University of Dalarna. To evaluate the driving behaviour in the parking lot direct observation was conducted to obtain overall indices of the parking lot vehicles movement. The parking route taken by the driver was compared with the optimal path to identify the driving behaviour in parking lot in terms of distance. The collected data was evaluated, filtered and analysed to identify the route, the distance and the time the vehicle takes to find a parking space. The outcome of the study shows that driving behaviour in the parking lots varies significantly among the parking user where most of the observed vehicles took unnecessary long time to complete their parking. The study shows that 56% of the 430 observed vehicles demonstrated inefficient driving behaviour as they took long driving path rather the than the optimal path. The study trace this behaviour to two factors, first, the absent of parking guidance in the parking lots and the second is the selectivity of the drivers when choosing the parking space. The study also shows that the ability of GPS data to identify the driving behaviour in the parking lots varies based on the time interval and the type of the device that is being used. The small the time interval the more accurate the GPS data in detecting the driving behaviour in the parking lots.
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Interpolation strategy based on Dynamic Time WarpingOperti, Felipe Gioachino January 2015 (has links)
OPERTI, Felipe Gioachino. Interpolation strategy based on Dynamic Time Warping. 2015. 53 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-04-14T22:11:14Z
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Previous issue date: 2015 / In oil industry, it is essential to have the knowledge of the stratified rocks’ lithology and, as consequence, where are placed the oil and the natural gases reserves, in order to efficiently drill the soil, without a major expense. In this context, the analysis of seismological data is highly relevant for the extraction of such hydrocarbons, producing predictions of profiles through reflection of mechanical waves in the soil. The image of the seismic mapping produced by wave refraction and reflection into the soil can be analysed to find geological formations of interest. In 1978, H. Sakoe et al. defined a model called Dynamic Time Warping (DTW)[23] for the local detection of similarity between two time series. We apply the Dynamic Time Warping Interpolation (DTWI) strategy to interpolate and simulate a seismic landscape formed by 129 depth-dependent sequences of length 201 using different values of known sequences m, where m = 2, 3, 5, 9, 17, 33, 65. For comparison, we done the same operation of interpolation using a Standard Linear Interpolation (SLI). Results show that the DTWI strategy works better than the SLI when m = 3, 5, 9, 17, or rather when distance between the known series has the same order size of the soil layers.
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Interpolation Strategy Based on Dynamic Time WarpingFelipe Gioachino Operti 29 January 2015 (has links)
In oil industry, it is essential to have the knowledge of the stratified rocksâ lithology and, as consequence, where are placed the oil and the natural gases reserves, in order to efficiently drill the soil, without a major expense. In this context, the analysis of seismological data is highly relevant for the extraction of such hydrocarbons, producing predictions of profiles through reflection of mechanical waves in the soil. The image of the seismic mapping produced by wave refraction and reflection into the soil can be analysed to find geological formations of interest. In 1978, H. Sakoe et al. defined a model called Dynamic Time Warping (DTW)[23] for the local detection of similarity between two time series. We apply the Dynamic Time Warping Interpolation (DTWI) strategy to interpolate and simulate a seismic landscape formed by 129 depth-dependent sequences of length 201 using different values of known sequences m, where m = 2, 3, 5, 9, 17, 33, 65. For comparison, we done the same operation of interpolation using a Standard Linear Interpolation (SLI). Results show that the DTWI strategy works better than the SLI when m = 3, 5, 9, 17, or rather when distance between the known series has the same order size of the soil layers.
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Maximal edge-traversal time in First Passage Percolation / ファーストパッセージパーコレーションの最大辺移動時間Nakajima, Shuta 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21543号 / 理博第4450号 / 新制||理||1639(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 福島 竜輝, 教授 熊谷 隆, 教授 牧野 和久 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Development of a 2D Optimal Path Simulation for Ship-to-Shore Cranes : Safe Trajectories within Interchangeable Obstalce EnvironmentsGreen, Rickard January 2020 (has links)
The most advanced ports as of writing of this report are at least somewhat autonomous. Whether discussing the transporters between crane and stack (temporary storage) or cranes, the ports are shifting into a completely autonomous system. This ultimate goal presents a challenge in regards to unloading and loading cargo ships in the harbour. How do you achieve unloading of a ship without human intervention while still guaranteeing secure trajectories for the containers? ABB Ports in collaboration with the Division of Vehicular Systems at Linköping University have developed a simulation that utilises a simple control model to investigate the behaviour, limitations and capabilities of such an autonomous crane. Specifically, this simulation utilises a model of the dynamics of a Ship-to-Shore crane (STS), which has the task of unloading a ship. In order to set the crane model in context of realistic scenarios, some additions to the simulation are needed. One of these additions is obstacles. Before this thesis work, the model enjoyed an empty simulation environment to freely optimise how quickly the containers could be transported off of the ship. The addition of obstacles in the form of other containers on the cargo ship as well as the physical presence of the crane’s legs presents new challenges for the optimiser used to solve the optimal control problems formulated through the model in the simulation. The implementation of obstacles is one of the objectives for this thesis. This addition was implemented by modeling the obstacle dimensions and ship limitations by looking at the largest container ships in the world. Due to the simulation not containing obstacles previous to this thesis work, the initial guess provided to the solver initialised the solving in an area of convergence that is unfair to the solver, This rendered the simulation useless, as any obstacle presented to the solver would generate an infeasible solution. Another functionality needed for the obstacle implementation to be meaningful is a solution for guaranteeing safe trajectories for the containers from ship to shore. The solution utilised to reach this goal was to combine a convex hull and safety conditions where the convex hull covers the obstacles, including some padding to prevent collisions between the container carried (load) and obstacles. The safety conditions however calculates the potential positions of the load when an emergency stop occurs, and therefore can prevent the load from swinging into obstacles if there is an emergency stop. These implementations however changes the usefulness and performance of the simulation because of how they shrink the area of convergence for the solver and making some problems non-solvable. When considering both a convex hull and safety conditions, the usability of the simulations is harmed, but can still be utilised to learn about autonomous performance of the simulation. The optimal solutions include some interesting characteristics that can learn crane operators about how the control systems can be utilised. Such a simulation would benefit from continuous development in order to investigate further technologies and features that could improve both performance and usability. Areas such as homotopy, modelling ropes, comparison between simple and nuanced model would be truly interesting for future areas of investigation.
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