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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Simulation in automated guided vehicle system design

Ujvári, Sándor January 2003 (has links)
No description available.
2

Should I Trust my Car? A Safety Perspective on Human-machine Interactions for Semi-autonomous Vehicles using Virtual Reality

Kennedy, Kendra Ann 01 August 2019 (has links)
With the increasingly rapid adoption of vehicles with autonomous features, concerns over human driver and passenger safety in such vehicles have greatly increased, especially in regards to autonomous driving features such as Tesla’s Autopilot. In order to improve current
3

Asean future mobility : Design a compatible future vehicle for pursuing of ASEAN´s ambition

Mohamad, Irfendy January 2016 (has links)
Starting a thesis with intention and ambitious to invent a future mobility for Southeast Asia region, one of the fastest growing region in the world. I was so passionate about what is the future mobility that very compatible to South-East Asia consumer that face a hot weather and humidity climate in whole year. Recently, the car that we produce whether in local manufacturing or imported car are not very compatible for the current environment since the climate is change dramatically in kind of temperature which massive impact in material usage in the vehicle and our daily life. By this platform, my main priority is to find a best solution by doing a research and problem´s analysis about the real situation and for a long period of time. Then, I was began the project by summarize the concept based on the research analysis. Design research, brand and background analysis, ideation sketches, studying an overall form by using clay and 3D digital modelling and also advanced visualization were the main methods that implemented during this project. The result is GEMILANG Concept, designed a future vehicle which have semi-autonomous drive mode for ASEAN ambition and actual need throughout in developing countries. The concept is considered between a climate change in this region and proposes a highly efficient in how to implement the best use of natural resources that able to stand in extreme climate particularly in this region and innovative solution between tradition, need and technology.
4

Real-Time Map Manipulation for Mobile Robot Navigation

Ezequiel, Carlos Favis 01 January 2013 (has links)
Mobile robots are gaining increased autonomy due to advances in sensor and computing technology. In their current form however, robots still lack algorithms for rapid perception of objects in a cluttered environment and can benefit from the assistance of a human operator. Further, fully autonomous systems will continue to be computationally expensive and costly for quite some time. Humans can visually assess objects and determine whether a certain path is traversable, but need not be involved in the low-level steering around any detected obstacles as is necessary in remote-controlled systems. If only used for rapid perception tasks, the operator could potentially assist several mobile robots performing various tasks such as exploration, surveillance, industrial work and search and rescue operations. There is a need to develop better human-robot interaction paradigms that would allow the human operator to effectively control and manage one or more mobile robots. This paper proposes a method of enhancing user effectiveness in controlling multiple mobile robots through real-time map manipulation. An interface is created that would allow a human operator to add virtual obstacles to the map that represents areas that the robot should avoid. A video camera is connected to the robot that would allow a human user to view the robot's environment. The combination of real-time map editing and live video streaming enables the robot to take advantage of human vision, which is still more effective at general object identification than current computer vision technology. Experimental results show that the robot is able to plan a faster path around an obstacle when the user marks the obstacle on the map, as opposed to allowing the robot to navigate on its own around an unmapped obstacle. Tests conducted on multiple users suggest that the accuracy in placing obstacles on the map decreases with increasing distance of the viewing apparatus from the obstacle. Despite this, the user can take advantage of landmarks found in the video and in the map in order to determine an obstacle's position on the map.
5

Autonomous Robotic Strategies for Urban Search and Rescue

Ryu, Kun Jin 16 November 2012 (has links)
This dissertation proposes autonomous robotic strategies for urban search and rescue (USAR) which are map-based semi-autonomous robot navigation and fully-autonomous robotic search, tracking, localization and mapping (STLAM) using a team of robots. Since the prerequisite for these solutions is accurate robot localization in the environment, this dissertation first presents a novel grid-based scan-to-map matching technique for accurate simultaneous localization and mapping (SLAM). At every acquisition of a new scan and estimation of the robot pose, the proposed technique corrects the estimation error by matching the new scan to the globally defined grid map. To improve the accuracy of the correction, each grid cell of the map is represented by multiple normal distributions (NDs). The new scan to be matched to the map is also represented by NDs, which achieves the scan-to-map matching by the ND-to-ND matching. In the map-based semi-autonomous robot navigation strategy, a robot placed in an environment creates the map of the environment and sends it to the human operator at a distant location. The human operator then makes decisions based on the map and controls the robot via tele-operation. In case of communication loss, the robot semi-autonomously returns to the home position by inversely tracking its trajectory with additional optimal path planning. In the fully-autonomous robotic solution to USAR, multiple robots communicate one another while operating together as a team. The base station collects information from each robot and assigns tasks to the robots. Unlike the semi-autonomous strategy there is no control from the human operator. To further enhance the efficiency of their cooperation each member of the team specifically works on its own task. A series of numerical and experimental studies were conducted to demonstrate the applicability of the proposed solutions to USAR scenarios. The effectiveness of the scan-to-map matching with the multi-ND representation was confirmed by analyzing the error accumulation and by comparing with the single-ND representation. The applicability of the scan-to-map matching to the real SLAM problem was also verified in three different real environments. The results of the map-based semi-autonomous robot navigation showed the effectiveness of the approach as an immediately usable solution to USAR. The effectiveness of the proposed fully- autonomous solution was first confirmed by two real robots in a real environment. The cooperative performance of the strategy was further investigated using the developed platform- and hardware-in-the-loop simulator. The results showed significant potential as the future solution to USAR. / Ph. D.
6

A Preliminary Investigation into using Artificial Neural Networks to Generate Surgical Trajectories to Enable Semi-Autonomous Surgery in Space

Korte, Christopher M. 15 October 2020 (has links)
No description available.
7

Equipes de trabalho com autonomia no Brasil: um estudo baseado em survey. / Self-managed teams in Brazil: a survey-based approach.

Simonetti, Paulo Eduardo 12 April 2007 (has links)
O tema desta dissertação é o trabalho em equipes com autonomia no Brasil. Percebe-se um ressurgimento do interesse pelo assunto a partir da década de 1990, no país e no exterior, movimento acompanhado pela produção científica nacional, em caráter qualitativo. Esta pesquisa adota uma abordagem quantitativa, do tipo survey, aplicada a uma amostra não-aleatória, intersetorial, de 49 empresas que reconhecem adotar o conceito de trabalho em equipes com autonomia. A partir da revisão da literatura foram desenvolvidas algumas questões de pesquisa e hipóteses, as quais estruturaram o questionário da pesquisa. Utilizando um instrumento já testado em estudos de caso, o questionário tem a capacidade de medir a abrangência e profundidade da autonomia das equipes, bem como: resultados obtidos, caracterização das empresas respondentes, iniciativa para adotar o conceito de autonomia e outras condições de contorno. O questionário foi concebido para ser enviado tanto pelo correio como por meio eletrônico e preenchido sem a presença do pesquisador. A partir da avaliação dos dados coletados, com auxílio de estatística descritiva e testes estatísticos indutivos, percebe-se equipes com grande autonomia, como no modelo Sociotécnico. A condição predominante, no entanto, é a transferência parcial de prerrogativas e responsabilidades às equipes, como no modelo Toyotista/Ohnoísta. Algumas evidências objetivas confirmam elementos da teoria, como a correlação positiva entre o grau de autonomia das equipes e resultados associados à capacidade superior de aprendizado e resposta a variações no ambiente. Informações relevantes sobre as características da amostra foram reveladas: a predominância de empresas de manufatura em grande escala, a significativa presença de empresas de capital nacional, a pequena participação do sindicato nos processos de implementação de equipes com autonomia, o crescente interesse pelo conceito, com demonstrado pelo perfil de \"idade\" dos projetos. As informações obtidas por meio desta pesquisa, bem como a experiência metodológica, podem servir de subsídio para futuros trabalhos sobre o tema, ou mesmo para outros temas, mas em pesquisas que utilizem o survey como método. / The subject of this dissertation is teamwork in Brazil. There has been a growing interest for the issue since the 1990 decade, in this country and abroad, followed by the national scientific production, of qualitative approach. This research project assumes survey-based approach, applied to a non-random, inter-sectorial sample, composed of 49 firms that recognize to adopt the concept oh teamwork. Some research questions and hypotesis were proposed, based on the literature review, as structure to the questionnaire. Making use of an instrument that was already tested by former case study, the questionnaire has the capacity to measure the deepness and the span of teams\' autonomy , as well as: results achieved, characteristics of the firms in the sample, initiative for the introduction of teamwork, and other surrounding conditions. The questionnaire was designed to be sent either by mail or by e-mail, and filled in the absence of the researcher. From the data evaluation, using descriptive statistics and also inductive statistics tests, are found some cases of teams with high degree of autonomy, in the fashion of Sociotechnical systems. The prevailing condition, nevertheless, is the partial transference of power and responsibilities to the work teams, like in the Toyota Production System. Some evidence were found that confirm theoretic elements, like the positive correlation between the degree of autonomy of work teams and specific results associated to the superior ability of learning and answering to variations of process or business conditions. Relevant information regarding the characteristics of the sample were also shown: the prevalence of large scale manufacturing companies, the significant incidence of national capital firms, the timid role that unions play on the introduction of teamwork, and the growing interest for the concept, as demonstrates the \"age\" profile of the teamwork initiatives. The information obtained by this research project, as well as the methodological experience, may serve as foundation to future projects regarding the subject \"teamwork\", or even to others that aim to use the survey approach.
8

Internet Fish

LaMacchia, Brian A. 01 August 1996 (has links)
I have invented "Internet Fish," a novel class of resource-discovery tools designed to help users extract useful information from the Internet. Internet Fish (IFish) are semi-autonomous, persistent information brokers; users deploy individual IFish to gather and refine information related to a particular topic. An IFish will initiate research, continue to discover new sources of information, and keep tabs on new developments in that topic. As part of the information-gathering process the user interacts with his IFish to find out what it has learned, answer questions it has posed, and make suggestions for guidance. Internet Fish differ from other Internet resource discovery systems in that they are persistent, personal and dynamic. As part of the information-gathering process IFish conduct extended, long-term conversations with users as they explore. They incorporate deep structural knowledge of the organization and services of the net, and are also capable of on-the-fly reconfiguration, modification and expansion. Human users may dynamically change the IFish in response to changes in the environment, or IFish may initiate such changes itself. IFish maintain internal state, including models of its own structure, behavior, information environment and its user; these models permit an IFish to perform meta-level reasoning about its own structure. To facilitate rapid assembly of particular IFish I have created the Internet Fish Construction Kit. This system provides enabling technology for the entire class of Internet Fish tools; it facilitates both creation of new IFish as well as additions of new capabilities to existing ones. The Construction Kit includes a collection of encapsulated heuristic knowledge modules that may be combined in mix-and-match fashion to create a particular IFish; interfaces to new services written with the Construction Kit may be immediately added to "live" IFish. Using the Construction Kit I have created a demonstration IFish specialized for finding World-Wide Web documents related to a given group of documents. This "Finder" IFish includes heuristics that describe how to interact with the Web in general, explain how to take advantage of various public indexes and classification schemes, and provide a method for discovering similarity relationships among documents.
9

Equipes de trabalho com autonomia no Brasil: um estudo baseado em survey. / Self-managed teams in Brazil: a survey-based approach.

Paulo Eduardo Simonetti 12 April 2007 (has links)
O tema desta dissertação é o trabalho em equipes com autonomia no Brasil. Percebe-se um ressurgimento do interesse pelo assunto a partir da década de 1990, no país e no exterior, movimento acompanhado pela produção científica nacional, em caráter qualitativo. Esta pesquisa adota uma abordagem quantitativa, do tipo survey, aplicada a uma amostra não-aleatória, intersetorial, de 49 empresas que reconhecem adotar o conceito de trabalho em equipes com autonomia. A partir da revisão da literatura foram desenvolvidas algumas questões de pesquisa e hipóteses, as quais estruturaram o questionário da pesquisa. Utilizando um instrumento já testado em estudos de caso, o questionário tem a capacidade de medir a abrangência e profundidade da autonomia das equipes, bem como: resultados obtidos, caracterização das empresas respondentes, iniciativa para adotar o conceito de autonomia e outras condições de contorno. O questionário foi concebido para ser enviado tanto pelo correio como por meio eletrônico e preenchido sem a presença do pesquisador. A partir da avaliação dos dados coletados, com auxílio de estatística descritiva e testes estatísticos indutivos, percebe-se equipes com grande autonomia, como no modelo Sociotécnico. A condição predominante, no entanto, é a transferência parcial de prerrogativas e responsabilidades às equipes, como no modelo Toyotista/Ohnoísta. Algumas evidências objetivas confirmam elementos da teoria, como a correlação positiva entre o grau de autonomia das equipes e resultados associados à capacidade superior de aprendizado e resposta a variações no ambiente. Informações relevantes sobre as características da amostra foram reveladas: a predominância de empresas de manufatura em grande escala, a significativa presença de empresas de capital nacional, a pequena participação do sindicato nos processos de implementação de equipes com autonomia, o crescente interesse pelo conceito, com demonstrado pelo perfil de \"idade\" dos projetos. As informações obtidas por meio desta pesquisa, bem como a experiência metodológica, podem servir de subsídio para futuros trabalhos sobre o tema, ou mesmo para outros temas, mas em pesquisas que utilizem o survey como método. / The subject of this dissertation is teamwork in Brazil. There has been a growing interest for the issue since the 1990 decade, in this country and abroad, followed by the national scientific production, of qualitative approach. This research project assumes survey-based approach, applied to a non-random, inter-sectorial sample, composed of 49 firms that recognize to adopt the concept oh teamwork. Some research questions and hypotesis were proposed, based on the literature review, as structure to the questionnaire. Making use of an instrument that was already tested by former case study, the questionnaire has the capacity to measure the deepness and the span of teams\' autonomy , as well as: results achieved, characteristics of the firms in the sample, initiative for the introduction of teamwork, and other surrounding conditions. The questionnaire was designed to be sent either by mail or by e-mail, and filled in the absence of the researcher. From the data evaluation, using descriptive statistics and also inductive statistics tests, are found some cases of teams with high degree of autonomy, in the fashion of Sociotechnical systems. The prevailing condition, nevertheless, is the partial transference of power and responsibilities to the work teams, like in the Toyota Production System. Some evidence were found that confirm theoretic elements, like the positive correlation between the degree of autonomy of work teams and specific results associated to the superior ability of learning and answering to variations of process or business conditions. Relevant information regarding the characteristics of the sample were also shown: the prevalence of large scale manufacturing companies, the significant incidence of national capital firms, the timid role that unions play on the introduction of teamwork, and the growing interest for the concept, as demonstrates the \"age\" profile of the teamwork initiatives. The information obtained by this research project, as well as the methodological experience, may serve as foundation to future projects regarding the subject \"teamwork\", or even to others that aim to use the survey approach.
10

Extending the Capabilities of Time Delayed Haptic Teleoperation Systems

Budolak, Daniel Wojciech 23 March 2020 (has links)
This thesis focuses on making improvements to time-delayed teleoperation systems, with both direct and semi-autonomous haptic control, by addressing the challenges associated with force-position (F-P) predictive architectures. As the time delay from the communication channel increases, system stability and performance degrade. Previously, solutions focused on communication channel stability and environment force estimation methods that primarily rely on linearization of the Hunt-Crossley (HC) contact model. These result in a loss of transparency in the system and limiting use cases from linearization assumptions. Moreover, semi-autonomous solutions aimed at decreasing user effort and automating subtasks, such as obstacle avoidance and user guidance, require training or singularly focus on joint space tasks. This work addresses the shortcomings of the aforementioned methods by refocusing on system components to achieve more favorable dynamics during environment contact with the use of a series elastic actuator (SEA), investigating alternative HC parameter estimation techniques, and synthesizing an assistive semi-autonomous control framework that predicts user intention recognition and automates gross motion tasks. Experimental results with a remote SEA demonstrate improved performance with stiff environments in delays of up to two seconds round trip time. The coupling of the force and position through the actuator along with simultaneous sensing capabilities also show robustness for contact with soft environments. Further improvements with soft environment contact are achieved through HC parameter estimation, with smooth parameter update switching using a Sigmoid function. A novel application of Chebyshev polynomial approximation for adaptive parameter estimation of the HC model was also proposed. This approach provides control via backstepping with adaptive parameter estimation using Lyapunov methods. Additionally, this method reduces excitation requirements by using nonlinear swapping and the data accumulation concept to guarantee parameter convergence. A simulated teleoperation system demonstrates the effectiveness of this approach and initial results from experiment show promise for this approach in practice. Finally, a user study involving a pick and place task produced favorable results for the proposed semi-autonomous framework which significantly reduced task completion times. / Master of Science / Teleoperated systems are powerful solutions for remotely executing tasks in situations where autonomous solutions are not robust enough and/or user knowledge is desired for a task. However, teleoperation performance and stability is degraded by delays in the communication channel. A common way to deal with time delay is to use a predictive controller on the local side to cancel out the delay by knowing the remote side dynamics. Previous approaches have focused on stabilizing the communication channel or the use of estimators and observers to better capture the remote side dynamics. The drawback of these approaches is that they achieve stability at the expense of system transparency, leading to divergence in the force and position matching between the master and remote side. Many of the methods for environment force estimation involves linearizing contact models, creating limitations in their application. Moreover, semi-autonomous solutions aimed at decreasing user effort and automating subtasks such as obstacle avoidance and user guidance require training data sets for the algorithm or only focus individually on joint space tasks. This thesis addresses the shortcomings of the aforementioned methods by refocusing on system components to achieve more favorable dynamics using a series elastic actuator (SEA) while interacting with the environment, investigating nonlinear and linear contact model estimation methods for identifying parameters of the Hunt-Crossley (HC) model, and synthesising an assistive semi-autonomous control framework that predicts user intention for task execution. Experimental results for the use of an SEA demonstrate improved performance with stiff environments in delays of up to two seconds round trip time (RTT). The coupling of the force and position through the actuator along with simultaneous sensing capabilities also showed robustness for contact with soft environments. Various estimation methods for HC parameter identification was investigated to improve the local side model. A novel application of Chebyshev polynomial approximation of the HC model with adaptive parameter estimation was also proposed to provide control along with decreasing the excitation requirements by using backsteping control with nonlinear swapping and the data accumulation concept. A simulated teleoperation system demonstrated the effectiveness of this approach with a smooth paramater update transition. Initial results from experiment also show promise for this approach in practice. Finally, a user study involving a pick and place task produced favorable results for the proposed semi-autonomous framework which significantly reduced task completion times.

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