• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 30
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 38
  • 38
  • 11
  • 10
  • 9
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
21

Identification of absolute orientation using inertial measurement unit

Kopfinger, André, Ahlsén, Daniel January 2019 (has links)
Because of the limitation of GPS indoors there is a demand for alternative methods to accurately determine both position and orientation. Previous attempts at positional tracking has required an infrastructure of hardware and sensors to provide the path of an object or person. This is not a mobile solution to a mobile problem. This project aims to answer the question if it is possible to use an Inertial measurement unit sensor for this application. It will also create a prototype device that will demonstrate the capabilities of the proposed method. The goal of the project is to reach an accuracy of ±20 cm for position and ±5 degrees for rotation. A Kalman filter will be used to filter the output from the sensor in order to get more stable and accurate readings. The results show that it is possible to determine position of ±20 cm up to 100 cm with the proposed method. An inertial measurement unit is capable of measuring rotation accuracy of ±5 degrees and a prototype has been designed and manufactured to demonstrate the method.
22

Towards a rough-fuzzy perception-based computing for vision-based indoor navigation

Duan, Tong 10 July 2014 (has links)
An indoor environment could be defined by a complex layout in a compact space. Since mobile robots can be used as substitute for human beings to access harmful and inaccessible locations, the research of autonomous indoor navigation has attracted much interest. In general, a mobile robot navigates in an indoor environment where acquired data are limited. Furthermore, sensor measurements may contain errors in a number of situations. Therefore, the complexity of indoor environment and ability of sensors have determined that it is an insufficient to merely compute with data. This thesis presents a new rough-fuzzy approach to perception-based computing for an indoor navigation algorithm. This approach to perceptual computing is being developed to store, analyze and summarize existing experience in given environment so that the machine is able to detect current situation and respond optimally. To improve uncertainty reasoning of fuzzy logic control, a rough set theory is integrated to regulate inputs before applying fuzzy inference rules. The behaviour extraction is evaluated and adjusted through entropy-based measures and multi-scale analysis. The rough-fuzzy based control algorithm aims to minimize overshoot and optimize transient-state period during navigation. The proposed algorithm is tested through simulations and experiments using practical common situations. The performance is evaluated with respect to desired path keeping and transient-state adaptability.
23

Autonomous Quadrotor Navigation by Detecting Vanishing Points in Indoor Environments

January 2018 (has links)
abstract: Toward the ambitious long-term goal of a fleet of cooperating Flexible Autonomous Machines operating in an uncertain Environment (FAME), this thesis addresses various perception and control problems in autonomous aerial robotics. The objective of this thesis is to motivate the use of perspective cues in single images for the planning and control of quadrotors in indoor environments. In addition to providing empirical evidence for the abundance of such cues in indoor environments, the usefulness of these perspective cues is demonstrated by designing a control algorithm for navigating a quadrotor in indoor corridors. An Extended Kalman Filter (EKF), implemented on top of the vision algorithm, serves to improve the robustness of the algorithm to changing illumination. In this thesis, vanishing points are the perspective cues used to control and navigate a quadrotor in an indoor corridor. Indoor corridors are an abundant source of parallel lines. As a consequence of perspective projection, parallel lines in the real world, that are not parallel to the plane of the camera, intersect at a point in the image. This point is called the vanishing point of the image. The vanishing point is sensitive to the lateral motion of the camera and hence the quadrotor. By tracking the position of the vanishing point in every image frame, the quadrotor can navigate along the center of the corridor. Experiments are conducted using the Augmented Reality (AR) Drone 2.0. The drone is equipped with the following componenets: (1) 720p forward facing camera for vanishing point detection, (2) 240p downward facing camera, (3) Inertial Measurement Unit (IMU) for attitude control , (4) Ultrasonic sensor for estimating altitude, (5) On-board 1 GHz Processor for processing low level commands. The reliability of the vision algorithm is presented by flying the drone in indoor corridors. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018
24

Designing an Augmented Reality Based Navigation Interface for Large Indoor Spaces

Curtsson, Fanny January 2021 (has links)
Navigating from one place to another is something we as humans do on an everyday basis, and modern technology has made it easier than ever by providing navigation tools in our mobile devices. In indoor spaces, augmented reality (AR) based navigation interfaces have shown a lot of potential, as it has been proven to increase efficiency and overall usability. However, there is a lack of research investigating how these types of interfaces should be designed to create a good user experience. This study aimed at providing more insight into this by exploring the usability of a mobile AR interface for indoor navigation through the Rapid Iterative Testing and Evaluation (RITE) method. In total, six participants tested the interface in three rounds of user testing and iteration, with two participants taking part in each round. The results showed that the usability increased with each iteration. Findings also reaffirmed the importance of minimizing the amount of information presented in the AR interface, by for example presenting information prior to the AR interface, as well as the value of adding support for occlusion. Moreover, confusion caused by how the virtual objects aligned with the real physical space showed the importance of testing on-site. / Att navigera från en plats till en annan är något vi människor gör varenda dag, och modern teknologi har gjort detta enklare än någonsin genom att erbjuda navigationsverktyg i våra mobila enheter. I inomhusmiljöer så har navigationsverktyg som använder förstärkt verklighet (AR) visat mycket potential, då det har visats ökat effektiviteten och den övergripliga användbarheten. Däremot finns det en brist på forskning som undersöker hur dessa typer av gränssnitt ska designas för att skapa en bra användarupplevelse. Denna studie syftade till att ge mer insikt i detta genom att utforska användbarheten av ett mobilt AR-gränssnitt för inomhusnavigering med hjälp av metoden Rapid Iterative Testing and Evaluation (RITE). en iterativ design och utvärderingsmetod. Totalt testade sex deltagare gränssnittet i tre omgångar av användartester, där två deltagare deltog i varje omgång. Resultaten visade att användbarheten ökade med varje iteration. Resultaten bekräftade även vikten av att minimera mängden information som presenteras i AR-gränssnittet, till exempel genom att presentera information innan AR-gränssnittet, samt värdet av att lägga till stöd för ocklusion. Vidare så visade även förvirringen kring hur de virtuella objekten relaterade till det riktiga fysiska utrymmet värdet av att testa på plats.
25

Evaluation of Mobile Augmented Reality for Indoor Navigation / Utvärdering av mobil förstärkt verklighet för inomhusnavigering

Wijkmark, Ruben, Hua, Alexander January 2019 (has links)
In the last three years, several advanced toolkits for developing mobile augmented reality applications have been released. This in combination with the increased computational power of commercially available mobile devices has led to a great surge of attention given to the development of such applications. Currently, most mobile augmented reality applications being developed are within the gaming category. In this study, one of the less popular use cases, indoor navigation, were explored. An initial literature study was carried out followed by the development of a prototype which were then evaluated through different usability tests. During the tests, the test subjects navigated partly with the use of the prototype and partly with traditional navigational aids present in the shopping mall where the testing took place. The test subjects navigated 28% faster on average when using the prototype and felt that it was more intuitive. Different negative aspects were, however, also observed such as a decreased awareness of their surroundings. In the end, mobile augmented reality was deemed to have great potential when used in the context of indoor navigation even though some technical challenges would likely need to be solved before widespread adoption could take place. / Under de senaste tre åren har flera avancerade verktyg för utveckling av mobilapplikationer med förstärkt verklighet lanserats. Detta i kombination med den ökade prestandan av kommersiellt tillgängliga mobila enheter har lett till en stor ökning av utvecklandet av sådana applikationer. För närvarande är majoriteten av de mobila applikationer med förstärkt verklighet som utvecklas inom kategorin spel. I denna studie undersöktes ett av de mindre populära användningsområdena, inomhusnavigering. Initialt utfördes en litteraturstudie följt av utvecklingen av en prototyp som sedan utvärderades genom olika användartester. Under testerna navigerade deltagarna dels med prototypen dels med de traditionella navigationshjälpmedel som fanns i köpcentret där testerna ägde rum. Deltagarna navigerade i genomsnitt 28% snabbare vid användning av prototypen och kände överlag att den var mer intuitiv att använda. Olika negativa aspekter med prototypen observerades såsom en minskad medvetenhet av omgivningen. I slutändan bedömdes mobilapplikationer med förstärkt verklighet ha stor potential vid användning för inomhusnavigering men att olika tekniska utmaningar sannolikt skulle behöva lösas före en mer utbredd användning av teknologin.
26

建構一以RFID定位之擴增實境系統 / Developing an augmented reality system based on rfid positioning

劉彥辰, Liu, Yen Chen Unknown Date (has links)
擴增實境的目的在於對真實環境做資訊的進一步擴充,發展技術中,主要面臨的挑戰為顯示方式、追蹤定位等,許多的技術限制使得發展逾三十年之擴增實境仍難以落實於日常生活中。近年來隨著智慧型手機的普及和軟硬體技術的發展,以擴增實境系統需要的顯示、通訊介面而言,智慧型手機具備發展行動式擴增實境的特點,致使許多擴增實境服務孕育而生,成為智慧型手機中重要的應用。然而目前應用於行動裝置的追蹤方式中,適用於戶外定位的全球衛星定位無法在室內精準定位,影像辨識的追蹤方式需倚賴實體辨識標籤的配置,使得少有在室內環境使用,及具完善行動性的擴增實境系統。本研究將針對擴增實境中追蹤定位方式加以擴充,增加擴增實境系統之適用範圍。 本研究運用RFID適用於室內環境定位之特點,使用LANDMARC方式進行定位計算,並實作定位環境的佈置,將RFID標籤作為環境中之定位點,計算出標的物以及使用者在環境中的位置,作為擴增實境的追蹤方式及顯示依據。系統平台以開放式平台Android進行開發,利用手機硬體中攝影鏡頭、三軸重力感測儀、通訊介面等支援,呈現擴增實境的畫面,其中將以虛擬物件標示出該標的物的實際位置,且可隨使用者及標的物間相對距離及角度進行調整,當使用者在環境中移動時,可即時的定位出所在位置,改變虛擬物件的標示。 本研究開發之系統目的在對真實環境中的實際位置或物件做資訊的擴充及指引,並提供即時性的互動,實驗結果中,此定位方式可達成較全球衛星定位(GPS)、無線網路定位(802.11)等更準確的定位結果,滿足在室內環境使用的行動型擴增實境系統追蹤定位之需求,未來可利用此顯示及追蹤方式,發展擴增實境更廣泛的應用。 / The purpose of Augmented Reality(AR) is to make further information adding to the real world. In its development, the main challenges are display, and tracking etc. Over three-decade developed, due to many technical constraints, AR still limited to apply widely in daily life. In recent years, as a result of the popularity of smart phones and its advancements of software and hardware, many AR services became important applications of smart phones. But in tracking techniques of mobile AR system, GPS cannot provide accurate positioning in indoor environment, image recognized method cannot provide mobile use. Therefore there are so few AR systems used in the indoor environment and possessed mobility. This study will be aimed at tracking methods of augmented reality and increasing the scope of AR application. This study use the feature of RFID positioning in indoor environment, and use LANDMARC method in position calculated. Make RFID tags as fiducial points in positioning environment, and calculate the object's as well as user's positions as the basis of display of AR system. In operating systems of smart phones, we use Android as our developing platform. By its supports of cameras, three-axis gravity sensor device, communication interfaces and others in mobile phone hardware, the system can show the overlayed virtual images of augmented reality. The actual location of the real object will be marked as a virtual object, which can be adjusted according to the distance and the angle between user and the position of real object. Also user will be located in real-time and the position of the virtual object will be adjusted when moves in the environment. The system can make further information augmented and interact instantly with locations or items in real environment. Experiment results verified that this tracking method can provide more accurate results compared to the global satellite positioning (GPS), wireless network locating (802.11) and other wireless uses. It can fulfill the demand of tracking in augmented reality system in indoor using. By the display and the tracking method, augmented reality applications can be more widely used in the future.
27

Indoor Navigation for Mobile Robots : Control and Representations

Althaus, Philipp January 2003 (has links)
This thesis deals with various aspects of indoor navigationfor mobile robots. For a system that moves around in ahousehold or office environment,two major problems must betackled. First, an appropriate control scheme has to bedesigned in order to navigate the platform. Second, the form ofrepresentations of the environment must be chosen. Behaviour based approaches have become the dominantmethodologies for designing control schemes for robotnavigation. One of them is the dynamical systems approach,which is based on the mathematical theory of nonlineardynamics. It provides a sound theoretical framework for bothbehaviour design and behaviour coordination. In the workpresented in this thesis, the approach has been used for thefirst time to construct a navigation system for realistic tasksin large-scale real-world environments. In particular, thecoordination scheme was exploited in order to combinecontinuous sensory signals and discrete events for decisionmaking processes. In addition, this coordination frameworkassures a continuous control signal at all times and permitsthe robot to deal with unexpected events. In order to act in the real world, the control system makesuse of representations of the environment. On the one hand,local geometrical representations parameterise the behaviours.On the other hand, context information and a predefined worldmodel enable the coordination scheme to switchbetweensubtasks. These representations constitute symbols, on thebasis of which the system makes decisions. These symbols mustbe anchored in the real world, requiring the capability ofrelating to sensory data. A general framework for theseanchoring processes in hybrid deliberative architectures isproposed. A distinction of anchoring on two different levels ofabstraction reduces the complexity of the problemsignificantly. A topological map was chosen as a world model. Through theadvanced behaviour coordination system and a proper choice ofrepresentations,the complexity of this map can be kept at aminimum. This allows the development of simple algorithms forautomatic map acquisition. When the robot is guided through theenvironment, it creates such a map of the area online. Theresulting map is precise enough for subsequent use innavigation. In addition, initial studies on navigation in human-robotinteraction tasks are presented. These kinds of tasks posedifferent constraints on a robotic system than, for example,delivery missions. It is shown that the methods developed inthis thesis can easily be applied to interactive navigation.Results show a personal robot maintaining formations with agroup of persons during social interaction. <b>Keywords:</b>mobile robots, robot navigation, indoornavigation, behaviour based robotics, hybrid deliberativesystems, dynamical systems approach, topological maps, symbolanchoring, autonomous mapping, human-robot interaction
28

Indoor Navigation for Mobile Robots : Control and Representations

Althaus, Philipp January 2003 (has links)
<p>This thesis deals with various aspects of indoor navigationfor mobile robots. For a system that moves around in ahousehold or office environment,two major problems must betackled. First, an appropriate control scheme has to bedesigned in order to navigate the platform. Second, the form ofrepresentations of the environment must be chosen.</p><p>Behaviour based approaches have become the dominantmethodologies for designing control schemes for robotnavigation. One of them is the dynamical systems approach,which is based on the mathematical theory of nonlineardynamics. It provides a sound theoretical framework for bothbehaviour design and behaviour coordination. In the workpresented in this thesis, the approach has been used for thefirst time to construct a navigation system for realistic tasksin large-scale real-world environments. In particular, thecoordination scheme was exploited in order to combinecontinuous sensory signals and discrete events for decisionmaking processes. In addition, this coordination frameworkassures a continuous control signal at all times and permitsthe robot to deal with unexpected events.</p><p>In order to act in the real world, the control system makesuse of representations of the environment. On the one hand,local geometrical representations parameterise the behaviours.On the other hand, context information and a predefined worldmodel enable the coordination scheme to switchbetweensubtasks. These representations constitute symbols, on thebasis of which the system makes decisions. These symbols mustbe anchored in the real world, requiring the capability ofrelating to sensory data. A general framework for theseanchoring processes in hybrid deliberative architectures isproposed. A distinction of anchoring on two different levels ofabstraction reduces the complexity of the problemsignificantly.</p><p>A topological map was chosen as a world model. Through theadvanced behaviour coordination system and a proper choice ofrepresentations,the complexity of this map can be kept at aminimum. This allows the development of simple algorithms forautomatic map acquisition. When the robot is guided through theenvironment, it creates such a map of the area online. Theresulting map is precise enough for subsequent use innavigation.</p><p>In addition, initial studies on navigation in human-robotinteraction tasks are presented. These kinds of tasks posedifferent constraints on a robotic system than, for example,delivery missions. It is shown that the methods developed inthis thesis can easily be applied to interactive navigation.Results show a personal robot maintaining formations with agroup of persons during social interaction.</p><p><b>Keywords:</b>mobile robots, robot navigation, indoornavigation, behaviour based robotics, hybrid deliberativesystems, dynamical systems approach, topological maps, symbolanchoring, autonomous mapping, human-robot interaction</p>
29

Návrh konstrukce mobilního autonomního robotu / Design of autonomous mobile robot.

Vodrážka, Jakub January 2010 (has links)
The thesis deals with design of the device for testing the localization techniques for indoor navigation. Autonomous robot was designed as the most appropriate platform for testing. The thesis is divided into three parts. The first one describes various kinds of robots, their possible use and sensors, which could be of use for solving the problem. The second part deals with the design and construction of the robot. The robot is built on the chassis of the differential type with support spur. Two electric motors with a gearbox and output shaft speed sensor represent the drive unit. Coat of the robot was designed for good functionality and attractive overall look. The robot is also used for the presentation of robotics. Thesis provides complete design of chassis and body construction, along with control section and sensorics. The last part describes a statistical model of the robot movement, which was based on several performed experiments. The experiments were realized to find any possible deviations of sensor measurement comparing to the real situation.
30

Increasing Autonomy of Unmanned Aircraft Systems Through the Use of Imaging Sensors

Rudol, Piotr January 2011 (has links)
The range of missions performed by Unmanned Aircraft Systems (UAS) has been steadily growing in the past decades thanks to continued development in several disciplines. The goal of increasing the autonomy of UAS's is widening the range of tasks which can be carried out without, or with minimal, external help. This thesis presents methods for increasing specific aspects of autonomy of UAS's operating both in outdoor and indoor environments where cameras are used as the primary sensors. First, a method for fusing color and thermal images for object detection, geolocation and tracking for UAS's operating primarily outdoors is presented. Specifically, a method for building saliency maps where human body locations are marked as points of interest is described. Such maps can be used in emergency situations to increase the situational awareness of first responders or a robotic system itself. Additionally, the same method is applied to the problem of vehicle tracking. A generated stream of geographical locations of tracked vehicles increases situational awareness by allowing for qualitative reasoning about, for example, vehicles overtaking, entering or leaving crossings. Second, two approaches to the UAS indoor localization problem in the absence of GPS-based positioning are presented. Both use cameras as the main sensors and enable autonomous indoor ight and navigation. The first approach takes advantage of cooperation with a ground robot to provide a UAS with its localization information. The second approach uses marker-based visual pose estimation where all computations are done onboard a small-scale aircraft which additionally increases its autonomy by not relying on external computational power.

Page generated in 0.1116 seconds