Alignment of optical system components using an ADM beam through a null assembly

A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical surface using the return light beam

Toward a compact underwater structured light 3-D imaging system

Thesis (S.B.)--Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 53-54).A compact underwater 3-D imaging system based on the principles of structured light was created for classroom demonstration and laboratory research purposes. The 3-D scanner design was based on research by the Hackengineer team at Rice University. The system is comprised of a low-power, open-source hardware single-board computer running a modified Linux distribution with OpenCV libraries, a DLP pico projector, camera board, and battery module with advanced power management. The system was designed to be low-cost, compact, and portable, while satisfying requirements for watertightness. Future development and applications may involve navigation systems for an autonomous underwater vehicle (AUV). An initial study of 3-D imaging methods is presented, and the strengths and drawbacks of each type are discussed. The structured light method was selected for further study for its ability to produce high-resolution 3-D images for a reasonable cost. The build of the 3-D imaging system was documented for reproducibility, and subsequent testing demonstrated its functions and ability to produce 3-D images. An instruction guide for operation of the device is provided for future classroom and laboratory use. The 3-D imaging system serves as a proof-of-concept for utilizing structured light methods to produce 3-D images underwater. Image resolution was limited by the output resolution of the pico projector and camera module. Further exploration in obtaining ultra high-resolution 3-D images may include use of a more powerful projector and a higher resolution camera board module with autofocus. Satisfactory 3-D scanning validated the performance of structured light scanning above water. However, contaminants in the water hindered accurate rendering by the system while submerged due to light scattering. Future development of a on-the-fly mapmaking system for AUV navigation should include algorithms for filtering light scattering, and hardware should based on an instantaneous structured light system utilizing the Kinect 2-D pattern method. Autofocus and increased projector brightness would also be worthwhile additions.by Geoffrey E. Dawson.S.B

Photometric stereo and appearance capture

Ph.DDOCTOR OF PHILOSOPH

Autonomous Operation and Human-Robot Interaction on an Indoor Mobile Robot

MARVIN (Mobile Autonomous Robotic Vehicle for Indoor Navigation) was once the flagship of Victoria University’s mobile robotic fleet. However, over the years MARVIN has become obsolete. This thesis continues the the redevelopment of MARVIN, transforming it into a fully autonomous research platform for human-robot interaction (HRI). MARVIN utilises a Segway RMP, a self balancing mobility platform. This provides agile locomotion, but increases sensor processing complexity due to its dynamic pitch. MARVIN’s existing sensing systems (including a laser rangefinder and ultrasonic sensors) are augmented with tactile sensors and a Microsoft Kinect v2 RGB-D camera for 3D sensing. This allows the detection of the obstacles often found in MARVIN’s unmodified office-like operating environment. These sensors are processed using novel techniques to account for the Segway’s dynamic pitch. A newly developed navigation stack takes the processed sensor data to facilitate localisation, obstacle detection and motion planning. MARVIN’s inherited humanoid robotic torso is augmented with a touch screen and voice interface, enabling HRI. MARVIN’s HRI capabilities are demonstrated by implementing it as a robotic guide. This implementation is evaluated through a usability study and found to be successful. Through evaluations of MARVIN’s locomotion, sensing, localisation and motion planning systems, in addition to the usability study, MARVIN is found to be capable of both autonomous navigation and engaging HRI. These developed features open a diverse range of research directions and HRI tasks that MARVIN can be used to explore

A property-based system design method with application to a targeting system for small UAVs

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.Includes bibliographical references (p. 251-253).The aim of system design is to define an optimal integration of components for the achievement of an overarching objective. As a result, engineering systems often cannot be designed with the disciplines meeting in isolation, but instead require collaboration for a synergism of goals, especially in aviation-based systems where tradeoffs are inherent to the design. Furthermore, defense-related projects require a strict acquisition process that requires companies to submit proposals for contracts. The system design method proposed here is geared towards the proposal stage of design and is aimed at enabling objective, informed design decisions. As such, the method uses the system's properties in a utility function-based evaluation to determine the best alternative. Towards these ends, the method defines criteria critical to the system's evaluation and functions to translate the system's properties related to these criteria into scores. The system's properties are derived from relationships with the components properties and between the components and their environment. As a result, the method translates component properties into system properties, which are then turned into scores.(Cont.) A utility function is used to create a total system utility for the alternative, which serves as the basis for comparison. A Python-based tool was written to facilitate the method, encapsulating the process in a high-level, easily configurable script. The method was demonstrated on the design of a targeting system for small UAVs. Three targeting methods were considered: assuming a flat Earth, using DTED data, and using range data. The evaluation revealed a descending utility order of DTED, Flat Earth, and Range based upon the system's stated requirements. While the Range method produced the most accurate results by far, its unit cost was well beyond the allocated budget, as was its power. DTED data was found to be a beneficial addition to small UAVs. In the evaluation, the method was able to elucidate the key information required to shape the design and thus showed promise.by Brian E. Mihok.S.M

A framework for surface metrology on Cultural Heritage objects based on scanning conoscopic holography

L'applicazione della metrologia di superficie e dell'analisi dimensionale allo studio dei beni culturali può rivelare importanti informazioni sull'oggetto e favorire l'integrazione di molteplici tecniche diagnostiche. Tuttavia, l'applicazione di queste discipline ai Beni Culturali richiede particolari requisiti e attenzioni. In questa tesi, presento i risultati dell'implementazione di diversi sistemi di misurazione della superficie basati sul principio della conoscopia olografica. I senori conoscopici sono strumenti capaci di misurare distanze con precisione micrometrica a scale diverse, accoppiati a slitte micrometriche possono essere utilizzati per acquisire scansioni areali dell'oggetto in esame. Per facilitare la loro applicazione alle opere d'arte ho sviluppato un extit{framework} per applicare la metrologia di superficie ai beni culturali. Il framework copre diversi aspetti del processo di analisi ed utilizzo dei dati e comprende la creazione di raccolte di campioni, le strategie per la scansione dell'oggetto, l'archiviazione e l'analisi dei dati ed eventualmente l'incertezza legata alla misura. Il extit{framework} mira a rendere più accessibile l'implementazione della metrologia di superficie e dei sistemi di scansione dell'analisi dimensionale per l'analisi dei beni culturali. I risultati raccolti su una varietà di materiali artistici (metalli, dipinti su tavola, tela, carta, pergamena e dipinti murali) mostrano come questi sistemi possano essere utilizzati per monitorare gli effetti delle procedure di pulitura, la stabilità dimensionale delle opere d'arte ed il loro invecchiamento.The application of surface metrology and dimensional analysis to the study of artworks can reveal important information on the object and aid the integration of multiple techniques. However, the application of these disciplines to Cultural Heritage objects necessitates particular care and requirements. In this dissertation, I present the results of the implementation of different systems, based on Conoscopic Holography range finders, for measuring the surface. Conoscopic holography range finders are viable instruments for measuring distances with micrometer accuracy at different scales, coupled with micrometric stages they can be used for acquiring areal scans of the object under investigation. To ease their application to artworks I built a framework for applying surface metrology to Cultural Heritage objects. The framework covers different aspects of the research workflow comprising the creation of samples collections, the strategies for scanning the object, the storing and the analysis of the data and eventually the uncertainty linked to the measurement. This framework aims to make more accessible the implementation of surface metrology and dimensional analysis scanning systems tailored to the analysis of Cultural Heritage objects. The results collected on a variety of artworks materials (metals, panels painting, canvas, paper, parchment and mural paintings) show how these systems can be used for monitoring the effects of cleaning procedures, the dimensional stability of the artworks and their ageing

An Application of Optical Interference to Dynamic Position Measurement in Three Dimensions

This thesis is concerned with the measurement of the positions of points and bodies moving in trajectories in three dimensions, and the use of a new technique of optical interference which allows such measurements to be made dynamically. A variety of existing techniques for both static and dynamic three-dimensional position measurement are discussed, and the design of the new interferometer is introduced. The geometry of points, curves and surfaces in three dimensions is examined, with emphasis on the intersection of the point loci represented by the coordinate output of measuring instruments. The coordinates output by the interferometer represent surface loci which are quadric surfaces. A method of calculating the position and orientation of a body using three quadric surface intersection curves is presented. Diffraction of monochromatic light at an aperture is considered and it is shown that an interferometer working by division of wavefront can be used to obtain continuous information about the movement of the source of radiation, with that source free to move in up to three dimensions. A lens may be used to produce a compact instrument based on these principles. The diffraction integral equations are modified to incorporate the effect of a lens in the diffraction field. It is shown that even complex lenses can be represented by a few parameters in the diffraction equations. From the evaluation of these diffraction integrals, it is shown how the movement of interference fringes provides a coordinate output and how this is related to the locus of the radiation source. A method of obtaining very high resolution measurements of interference fringe pattern movement is presented. The interferometer was built and tested and the above theory verified in practice in a series of optical bench tests. The implementation of a system which uses this interferometer to measure the dynamic performance of industrial robots is considered. The optimum positions for the instruments are derived, and the method of designing the interferometer to give the required resolution is presented

Interactive physical agents for story gathering

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 117-118).Robots are typically thought of as autonomous devices which require little to no human interaction to complete their goals. In this study we investigated what would happen if the success of a robot was contingent upon its interaction with a human. How do we leverage humans to make robots more intelligent, efficient and successful? Is it worth it to involve human heavily in the goals of a system? This thesis we presents a method for the creation of a physical agent to facilitate interaction and documentary gathering within a ubiquitous media framework as a method for studying human dependent systems. We built a robot and sent it out to autonomously capture stories about its environment. The robot had a specific story capture goal and leveraged humans to attain that goal. The robot gathered a 1st person view of stories unfolding in real life. We evaluated this agent by way of determining "complete" vs. "incomplete" interactions. "Complete" interactions were those that generated viable and interesting videos, which could be edited together into a larger narrative. It was found that 30% of the interactions captured were "complete" interactions. Results suggested that changes in the system would only produce incrementally more "complete" interactions, as external factors like natural bias or busyness of the user come into play. The types of users who encountered the robot were fairly polar; either they wanted to interact or did not - very few partial interactions went on for more than 1 minute. Users who partially interacted with the robot were found to treat it rougher than those who completed the full interaction. It was also determined that this type of limited-interaction system is best suited for short-term interactions. At the end of the study, a movie was produced from the videos captured, proving that they were viable for story-making.by Alexander James Reben.S.M

Human estimation of slope, distance, and height of terrain in simulated lunar conditions

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2009.Includes bibliographical references (p. 161-166).As NASA's Vision for Space Exploration seeks to explore mountainous regions near the southern pole through frequent, long excursions, astronauts will require accurate navigational assistance. Current and future technology, including LIDAR data, laser rangefinders, and path planning programs will likely be available; however, the human's own perception of the terrain may affect their confidence in these instruments and be necessary during emergency situations. These unique lunar conditions are expected to affect human perception: the lack of an atmosphere (inhibiting the use of aerial perspective as a distance cue and causing the formation of deep cast shadows), the non-Lambertian regolith reflectance properties, the lack of familiar objects, and the physiological effects of reduced gravity. This project examines the inherent errors humans make when judging the slope, distance, and height of terrain, both on the Earth in a lunar-like environment and on the Moon using photographs from the Apollo missions. Five experiments were conducted in field and Virtual Reality (VR) environments. The effects of true slope, true distance, and sun elevation on slope estimates were determined using visual and motor responses in a lunar-like Utah environment and reproduced in a VR environment using synoptically viewed images in two body positions, under normal and lunar Gz loading conditions. The effects of true slope, distance, and body position on slope, distance, and height estimates of synoptically viewed Apollo panoramic images were measured and compared to measurements obtained from topographical maps. Systematic and random errors were determined for all estimates. Slope estimate comparisons were made between lunar-like and lunar terrain and also between lunar hills and craters. Slope was significantly overestimated in the field study by 130 - 230 with large between-subject errors.(cont.) Lunar-like field and VR slope estimates were not significantly different from each other. Slope estimates were significantly greater at lower sun elevations and closer distances in the Lunar-like VR Study. Both slope and distance estimates were significantly greater from a lunar Gz supine position. Lunar distance estimates varied largely and slope estimation errors were significantly greater for craters than for hills. A new relationsihp between hill shape and perceived steepness was also discovered. The recommendations of this study include the development of a VR training tool to calibrate an astronaut's slope, distance, and height perception prior to lunar missions and future field studies at Devon Island to determine the effect of hill shape on estimates and to determine the regression coefficients of sun elevation and distance variables to be used in a model integrated with rangefinding devices in a Heads-Up-Display (HUD).by Christopher Oravetz.S.M