ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / The paper describes the development of a robotic platform which can autonomously map terrain using a COTS infrared imaging and ranging system. The robotic system is based on an omnidirectional platform, and can navigate typical commercial indoor environments. An on-board processor performs surface reconstruction, and condenses the point clouds generated by the ranging system to mesh models which can be more easily stored and transmitted. The processor then correlates new frames with the existing world model by using sensor odomerty. The robot will autonomously determine the best areas of the environment to map, and gather complete three dimensional color models of arbitrary environments.

When considering the operation of an Unmanned Aerial Vehicle (UAV) or an Unmanned Ground Vehicle (UGV), such problems as landing site estimation or robot path planning become a concern. Deciding if an area of terrain has a level enough slope and a wide enough area to land a Vertical Take Off and Landing (VTOL) UAV or if an area of terrain is traversable by a ground robot is reliant on data gathered from sensors, such as cameras. 3-D models, which can be built from data extracted from digital cameras, can help facilitate decision making for such tasks by providing a virtual model of the surrounding environment the system is in. A stereo vision system utilizes two or more cameras, which capture images of a scene from two or more viewpoints, to create 3-D point clouds. A point cloud is a set of un-gridded 3-D points corresponding to a 2-D image, and is used to build gridded surface models. Designing a stereo system for distant terrain modeling requires an extended baseline, or distance between the two cameras, in order to obtain a reasonable depth resolution. As the width of the baseline increases, so does the flexibility of the system, causing the orientation of the cameras to deviate from their original state. A set of tools have been developed to generate 3-D point clouds from rigid and flexible stereo systems, along with a method for applying corrections to a flexible system to regain distance accuracy in a flexible system. / Master of Science

This thesis presents a new method for improved resolution of stereoscopic 3D terrain mapping by local dense bundling of disparity maps. The Unmanned Systems Lab (USL) at Virginia Tech is designing an unmanned aerial vehicle (UAV) first-response system capable of 3D terrain mapping in the wake of a nuclear event. The UAV is a helicopter, and is equipped with a stereo boom imaging system, GPS, and an inertial measurement system (IMU) for low-altitude aerial mapping. Previous 3D reconstruction algorithms on the project used two-frame rectified stereo correspondence to create a local 3D map, which was geo-located by raw GPS and IMU data. The new local dense bundling algo-rithm combines multiple pairs of stereo images by SURF feature point matching, image rectification, matching of dense points with semi-global block matching, and optimization of camera pose and dense 3D point location using a stereo-constrained local bundle adjustment. The performance of the algorithm is evaluated numerically on synthetic im-agery and qualitatively on real aerial flight data. Results indicate the algorithm produces marked improvement in accuracy and vertical resolution, given a proper helicopter flight path and sufficient image overlap. With synthetic imagery and precise pose supplied, the algorithm shows a 1.2x to 6x reduction in vertical error. / Master of Science

This paper presents a new approach to the feature-matching problem for 3D reconstruction by taking advantage of GPS and IMU data, along with a prior calibrated stereo camera system. It is expected that pose estimates and calibration can be used to increase feature matching speed and accuracy. Given pose estimates of cameras and extracted features from images, the algorithm first enumerates feature matches based on stereo projection constraints in 2D and then backprojects them to 3D. Then, a grid search algorithm over potential camera poses is proposed to match the 3D features and find the largest group of 3D feature matches between pairs of stereo frames. This approach will provide pose accuracy to within the space that each grid region covers. Further refinement of relative camera poses is performed with an iteratively re-weighted least squares (IRLS) method in order to reject outliers in the 3D matches. The algorithm is shown to be capable of running in real-time correctly, where the majority of processing time is taken by feature extraction and description. The method is shown to outperform standard open source software for reconstruction from imagery. / Master of Science

Technical advancements in 3D projection has recently made presentation of holographic images possible by using self-contained devices. Instead of using a screen to present objects, glasses like Microsoft HoloLens can render objects that appear as holograms around the user. SAAB Defence and Security are evaluating if this new technology can complement their command and control system 9LV Combat Management System. This degree project is a study of the technical possibilities and limitations of introducing holographic display of sonar tracks used for detecting submarines or sea mines. The project was started with a background study into what methods are available to render 3D underwater terrain. A basic hologram representing a map of littoral terrain was constructed and simulated sonar tracks from the command and control system was mapped into the terrain. Implementation of the application was done using the Unity 3D game engine that has built in support for the HoloLens. Performance evaluation was done using Unity3D profiler that is an extensive application evaluation tool that maintain overhead to a minimum. An evaluation of HoloLens usage onboard two different boats was done to conclude if the equipment can be used in the normal 9LV CMS operating environment. Results show that it is possible to successfully use holographic display for sonar tracks, but due to limited processing power of the HoloLens terrain detail will be reduced. Holograms are orientated by combining camera spatial mapping and an inertial measurement unit. Usage tests onboard a vessel indicates that holograms will unexpectedly move and the HoloLens will loose spatial mapping due to acceleration forces caused by seastate. / Tekniska framsteg inom presentation av 3D-objekt har nyligen möjliggjort användning av hologram presenterade med portabel utrustning. Istället för att använda en vanlig skärm kan glasögon, som Microsoft HoloLens, rendera objekt som användaren upplever i sin omgivning som hologram. SAAB Defence and Security utvärderar om den nya teknologin kan användas som ett komplement till deras ledningssystem 9LV Combat Management System. Det här examensarbetet är en studie av de tekniska möjligheter och begränsningar som finns för att bygga en applikation som visar sonar-information som ett hologram, främst att användas för ubåtsjakt och upptäckt av sjöminor. Projektet inleddes med en bakgrundsstudie om vilka metoder som finns tillgängliga för att rendera en 3D-karta av en havsbotten. En enkel applikation med en karta som föreställer en del av skärgården tas fram med simulerad sonar-information från ledningssystemet inlagt i kartan. Implementationen av applikationen gjordes med spelmotorn Unity3D som har inbyggt stöd för Microsoft HoloLens. Prestandautvärdering genomfördes genom att använda ett inbyggt profileringsverktyg i Unity3D som har liten påverkan på prestandan. Utvärdering av möjlig användningsmiljö gjordes genom att testa utrustningen ombord på två olika båtar för att avgöra om HoloLens kan användas i 9LV CMS normala operativa förhållanden. Resultaten visar att det är möjligt att använda holografisk visning för sonar-data men upplösningen av terrängen för kartan är något låg på grund av den begränsade beräkningskraften i Microsoft HoloLens. Hologram i Microsoft HoloLens orienteras genom att kombinera en djupseende kamera med en intern referensenhet. Användningstester ombord på båt visar på att vid accelerationer som uppkommer av sjöhävning tappar HoloLensen rumsuppfattningen tillfälligt och stoppar renderingen av hologrammet.