Dissertations / Theses on the topic 'Mobile Mapping System (MMS)'
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Centový, Radoslav. "Analýza trajektorie mobilních mapovacích platforem." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-390215.
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The diploma thesis deals with possibilities of tracing the trajectory of mobile mapping systems in order to compare their accuracy. This thesis discusses the individual components of the mobile mapping device that were used in its construction. The thesis contains the results of the experiments that were performed on individual test.
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Poreba, Martyna. "Qualification et amélioration de la précision de systèmes de balayage laser mobiles par extraction d’arêtes." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0012/document.
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Au cours de ces dernières décennies, le développement de Systèmes Mobiles de Cartographie, soutenu par un progrès technologique important, est devenu plus apparent. Il a été stimulé par le besoin grandissant de collecte d'informations géographiques précises sur l'environnement. Nous considérons, au sein de cette thèse, des solutions pour l'acquisition des nuages de points mobiles de qualité topographique (précision centimétrique). Il s'agit, dans cette tâche, de mettre au point des méthodes de qualification des données, et d'en améliorer sur les erreurs systématiques par des techniques d'étalonnage et de recalage adéquates.Nous décrivons une démarche innovante d'évaluation de l'exactitude et/ou de la précision des relevés laser mobiles. Celle-ci repose sur l'extraction et la comparaison des entités linéaires de la scène urbaine. La distance moyenne calculée entre les segments appariés, étant la distance modifiée de Hausdorff, sert à noter les nuages par rapport à des références existantes. Pour l'extraction des arêtes, nous proposons une méthode de détection d'intersections entre segments plans retrouvés via un algorithme de RANSAC enrichi d'une analyse de composantes connexes. Nous envisageons également une démarche de correction de relevés laser mobiles à travers un recalage rigide fondé, lui aussi, sur les éléments linéaires. Enfin, nous étudions la pertinence des segments pour en déduire les paramètres de l'étalonnage extrinsèque du système mobile. Nous testons nos méthodes sur des données simulées et des données réelles acquises dans le cadre du projet TerraMobilitaOver the past few decades, the development of land-based Mobile Mapping Systems (MMS), supported by significant technological progress, has become more prominent. It has been motivated by the growing need for precise geographic information about the environment. In this thesis, we consider approaches for the acquisition of mobile point clouds with topographic quality (centimeter-level accuracy). The aim is to develop techniques for data quality assessment and improvement. In particular, we eliminate the systematic errors inherent to an MMS data using appropriate calibration and registration methods.We describe a novel approach to assess the accuracy and/or the precision of mobile laser point clouds. It is based on the extraction and comparison of line features detected within the urban scene. The computed average distance between corresponding pairs of line segments, taking advantage of a modified Hausdorff distance, is used to evaluate the MMS data with respect to a reference data set. For edge extraction, we propose a method which relies on the intersections between planes modelled via the RANSAC algorithm refined by an analysis of connected components. We also consider an approach to correct point clouds using a line-based rigid registration method. Finally, we study the use of line segments for estimating the boresight angles of a land-based mobile mapping system. We apply our methods to synthetic data and to real data acquired as part of the TerraMobilita project
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Ceroni, Rodrigo. "Mobile Mapping System." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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Nella tesi si espone il Mobile Mapping System, cioè il rilevamento di dati geospaziali utilizzando sensori montati a bordo di appositi veicolo senza l'ausilio di punti di contatto a terra.
Si illustrano i diversi dispositivi del sistema installati a bordo, le loro diverse applicazioni e metodologie di rilevamento.
Si trattano le varie problematiche sorte e le loro risoluzioni.
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Singh, Kuljeet. "LIVESMOBILE : extending the LIVES system to support SMS and MMS for mobile learning." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/30756.
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The past decade has seen a proliferation of cellular devices actively being used in
day to day lives by people in developing nations. Education however still remains
a challenge as children are either deprived of basic education or are victims of
favoritism due to deep-rooted inequalities linked to family wealth, gender, ethnicity,
language and location. Less educated adults face problems due to lack of
skills or qualifications required to get decent jobs. The proper use of educational
material can tackle some of these problems and in general improve the general
quality of life amongst this section of the population. Learning through Interactive
Voice Education System (LIVES) is a system developed at the University of
British Columbia (UBC) which aims at providing education to people in developing
countries by using voice-based lessons delivered using a pre-existing mobile
phone infrastructure. LIVES offers a two-way communication channel between
the user and the system and thus has the ability to offer a customized learning
experience based on the users’ preferences. In the LIVES system, this customization
is offered by providing the user with a list of options through the use of voice
dialogues within calls at which the user chooses a particular option. In this thesis, we propose a way to integrate Short Message Service (SMS) and Multimedia
Message Service (MMS) into the LIVES system to enhance the learning experience
of the end-user. By using SMS, we propose that the user can customize his
learning experience in ways which are hard to achieve through voice. Moreover,
the addition of MMS to the LIVES system provides an additional mechanism for
content delivery to the student. We propose that the addition of MMS capability to
the LIVES system can tackle some of the challenges faced during content delivery
by using voice as a delivery mechanism.
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Chaplin, Bruce Alan. "Motion estimation from stereo image sequences for a mobile mapping system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0020/MQ48058.pdf.
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Tavasci, Luca. "Metodi per l'ottimizzazione di rilievi Mobile Mapping System in aree urbane." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amslaurea.unibo.it/335/.
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Gomes, Pedro Miguel de Barros. "LADAR based mapping and obstacle detection system for service robots." Master's thesis, Faculdade de Ciências e Tecnologia, 2010. http://hdl.handle.net/10362/4589.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresWhen travelling in unfamiliar environments, a mobile service robot needs to acquire information about his surroundings in order to detect and avoid obstacles and arrive safely at his destination. This dissertation presents a solution for the problem of mapping and obstacle detection in indoor/outdoor structured3 environments, with particular application on service robots equipped with a LADAR. Since this system was designed for structured environments, offroad terrains are outside the scope of this work. Also, the use of any a priori knowledge about LADAR’s surroundings is discarded, i.e. the developed mapping and obstacle detection system works in unknown environments. In this solution, it is assumed that the robot, which carries the LADAR and the mapping and obstacle detection system, is based on a planar surface which is considered to be the ground plane. The LADAR is positioned in a way suitable for a three dimensional world and an AHRS sensor is used to increase the robustness of the system to variations on robot’s attitude, which, in turn, can cause false positives on obstacle detection. The results from the experimental tests conducted in real environments through the incorporation on a physical robot suggest that the developed solution can be a good option for service robots driving in indoor/outdoor structured environments.
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Soheilian, Khorzoughi Bahman. "Roadmark reconstruction from stereo-images acquired by a ground-based mobile mapping system." Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00296601.
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Despite advances in ground-based Mobile Mapping System (MMS), automatic feature reconstruction seems far from being reached. In this thesis, we focus on 3D roadmark reconstruction from images acquired by road looking cameras of a MMS stereo-rig in dense urban context. A new approach is presented, that uses 3D geometric knowledge of roadmarks and provides a centimetric 3D accuracy with a low level of generalisation. Two classes of roadmarks are studied: zebra-crossing and dashed-lines. The general strategy consists in three main steps. The first step provides 3D linked-edges. Edges are extracted in the left and right images. Then a matching algorithm that is based on dynamic programming optimisation matches the edges between the two images. A sub-pixel matching is computed by post processing and 3D linked-edges are provided by classical photogrammetric triangulation. The second step uses the known specification of roadmarks to perform a signature based filtering of 3D linked-edges. This step provides hypothetical candidates for roadmark objects. The last step can be seen as a validation step that rejects or accepts the candidates. The validated candidates are finely reconstructed. The adopted model consists of a quasi parallelogram for each strip of zebra-crossing or dashed-line. Each strip is constrained to be flat but the roadmark as a whole is not planar. The method is evaluated on a set of 150 stereo-pairs acquired in a real urban area under normal traffic conditions. The results show the validity of the approach in terms of robustness, completeness and geometric accuracy. The method is robust and deals properly with partially occluded roadmarks as well as damaged or eroded ones. The detection rate reaches 90% and the 3D accuracy is about 2-4 cm. Finally an application of reconstructed roadmarks is presented. They are used in georeferencing of the system. Most of the MMSs use direct georeferencing devices such as GPS/INS for their localisation. However in urban areas masks and multi-path errors corrupt the measurements and provide only 50 cm accuracy. In order to improve the localisation quality, we aim at matching ground-based images with calibrated aerial images of the same area. For this purpose roadmarks are used as matching objects. The validity of this method is demonstrated on a zebra-crossing example
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Soheilian, Bahman. "Roadmark reconstruction from stereo-images acquired by a ground-based mobile mapping system." Thesis, Paris Est, 2008. http://www.theses.fr/2008PEST0260/document.
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Malgré les récentes avancées des Systèmes de Cartographie Mobile, la reconstruction automatique d’objets à partir des données acquises est encore un point crucial. Dans cette thèse, nous nous intéresserons en particulier à la reconstruction tridimensionnelle du marquage au sol à partir d’images acquises sur le réseau routier par une base stéréoscopique horizontale d’un système de cartographie mobile, dans un contexte urbain dense. Une nouvelle approche s’appuyant sur la connaissance de la géométrie 3D des marquages au sol est présentée, conduisant à une précision de reconstruction 3D centimétrique avec un faible niveau de généralisation. Deux objets de la signalisation routière horizontale sont étudiés : les passages piétons et les lignes blanches discontinues. La stratégie générale est composée de trois grandes étapes. La première d’entre elles permet d’obtenir des chaînes de contours 3D. Les contours sont extraits dans les images gauche et droite. Ensuite, un algorithme reposant sur une optimisation par programmation dynamique est mis en oeuvre pour apparier les points de contours des deux images. Un post-traitement permet un appariement sub-pixellique, et, les chaînes de contours 3D sont finalement obtenues par une triangulation photogrammétrique classique. La seconde étape fait intervenir les spécifications géométriques des marquages au sol pour réaliser un filtrage des chaînes de contours 3D. Elle permet de déterminer des candidats pour les objets du marquage au sol. La dernière étape peut être vue comme une validation permettant de rejeter ou d’accepter ces hypothèses. Les candidats retenus sont alors reconstruits finement. Pour chaque bande d’un passage piéton ou d’une ligne discontinue, le modèle est un quasi-parallélogramme. Une contrainte de planéité est imposée aux sommets de chaque bande, ce qui n’est pas le cas pour l’ensemble des bandes formant un marquage au sol particulier. La méthode est évaluée sur un ensemble de 150 paires d’images acquises en centre ville dans des conditions normales de trafic. Les résultats montrent la validité de notre stratégie en terme de robustesse, de complétude et de précision géométrique. La méthode est robuste et permet de gérer les occultations partielles ainsi que les marquages usés ou abîmés. Le taux de détection atteint 90% et la précision de reconstruction 3D est de l’ordre de 2 à 4 cm. Finalement, une application de la reconstruction des marquages au sol est présentée : le géoréférencement du système d’acquisition. La majorité des systèmes de cartographie mobile utilisent des capteurs de géoréférencement direct comme un couplage GPS/INS pour leur localisation. Cependant, en milieu urbain dense, les masques et les multi-trajets corrompent les mesures et conduisent à une précision d’environ 50 cm. Afin d’améliorer la qualité de localisation, nous cherchons à apparier les images terrestres avec des images aériennes calibrées de la même zone. Les marquages au sol sont alors utilisés comme objets d’appariement. La validité de la méthode est démontrée sur un exemple de passage piétonDespite advances in ground-based Mobile Mapping System (MMS), automatic feature reconstruction seems far from being reached. In this thesis, we focus on 3D roadmark reconstruction from images acquired by road looking cameras of a MMS stereo-rig in dense urban context. A new approach is presented, that uses 3D geometric knowledge of roadmarks and provides a centimetric 3D accuracy with a low level of generalisation. Two classes of roadmarks are studied: zebra-crossing and dashed-lines. The general strategy consists in three main steps. The first step provides 3D linked-edges. Edges are extracted in the left and right images. Then a matching algorithm that is based on dynamic programming optimisation matches the edges between the two images. A sub-pixel matching is computed by post processing and 3D linked-edges are provided by classical photogrammetric triangulation. The second step uses the known specification of roadmarks to perform a signature based filtering of 3D linked-edges. This step provides hypothetical candidates for roadmark objects. The last step can be seen as a validation step that rejects or accepts the candidates. The validated candidates are finely reconstructed. The adopted model consists of a quasi parallelogram for each strip of zebra-crossing or dashed-line. Each strip is constrained to be flat but the roadmark as a whole is not planar. The method is evaluated on a set of 150 stereo-pairs acquired in a real urban area under normal traffic conditions. The results show the validity of the approach in terms of robustness, completeness and geometric accuracy. The method is robust and deals properly with partially occluded roadmarks as well as damaged or eroded ones. The detection rate reaches 90% and the 3D accuracy is about 2-4 cm. Finally an application of reconstructed roadmarks is presented. They are used in georeferencing of the system. Most of the MMSs use direct georeferencing devices such as GPS/INS for their localisation. However in urban areas masks and multi-path errors corrupt the measurements and provide only 50 cm accuracy. In order to improve the localisation quality, we aim at matching ground-based images with calibrated aerial images of the same area. For this purpose roadmarks are used as matching objects. The validity of this method is demonstrated on a zebra-crossing example
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Barry, Jeremy Jude. "Map Creation and Position Correction for an Off the Shelf Mobile Robotic System." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33063.
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Robots are widely used in domestic and commercial applications. These applications typically involve robots built for a specific the task, thus leading to efficiency in task completion. However, with the increase in completion efficiency comes an increase in the time required for completion of the whole system. Specific tasks create the need for many different robots, all with differing capabilities, causing an increase in development cost and time needed.
This raises the issue of whether using an off the shelf system with minor modifications can accurately perform the same tasks. If so, more time can be spent on refining the process leading to completion of the task, resulting in less time spent developing the robot. Consequently, less cost in the life cycle of the system leads to less cost for the end user, thus allowing robots to be used for more applications.
This thesis explores using a commercially available robot, Acroname Inc.â s Garcia, to perform mapping and localization tasks. As the robot travels it gathers data about the environment. This data is processed in Matlab and the result of the algorithm is a map. In the creation of the map, mathematical morphology is explored as a means to reduce noise. When the robot has located a corner, Matlab provides the robot with a position estimate correction. This correction allows the robot to better estimate its location resulting in a more accurate map. As the results of this thesis illustrate, with very minor modifications, the robot is capable of accurately performing mapping and localization tasks. The results demonstrate that an off the shelf system is capable of accurately performing tasks for which it was not specifically designed.
Master of Science
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Al, Shaiba Omar. "Update urban basemap by using the LiDAR mobile mapping system : the case of Abu Dhabi municipal system." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669771.
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Basemaps are the main resource used in urban planning and in building and infrastructure asset management. These maps are used by citizens and by private and public stakeholders. Therefore, accurate, up-to-date geoinformation of reference are needed to provide a good service.
In general, basemaps have been updated by aerial photogrammetry or field surveying, but these methods are not always possible and alternatives need to be sought. Current limitations and challenges that face traditional field surveys include areas with extreme weather, deserts or artic environments, and flight restrictions due to proximity with other countries if there is not an agreement. In such cases, alternatives for large-scale are required.
This thesis proposes the use of a mobile mapping system (MMS) to update urban basemaps. Most urban features can be extracted from point cloud using commercial software or open libraries. However, there are some exceptions: manhole covers, or hidden elements even with captures from defferent perspective, the most common building corners. Therefore, the main objective of this study was to establish a methodology for extracting manholes automatically and for completing hidden corners of buildings, so that urban basemaps can be updated. The algorithm developed to extract manholes is based on time, intensity and shape detection parameters, whereas additional information from satellite images is used to complete buildings.
Each municipality knows the materials and dimensions of its manholes. Taking advantage of this knowledge, the point cloud is filtered to classify points according to the set of intensity values associated with the manhole material. From the classified points, the minimum bounding rectangles (MBR) are obtained and finally the shape is adjusted and drawn.
We use satellite imagery to automatically digitize the layout of building footprints with automated software tools. Then, the visible corners of buildings from the LiDAR point cloud are imported and a fitting process is performed by comparing them with the corners of the building from the satellite image. Two methods are evaluated to establish which is the most suitable for adjustment in these conditions. In the first method, the differences in X and Y directions are measured in the corners, where LiDAR and satellite data are available, and is often computed as the average of the offsets. In the second method, a Helmert 2D transformation is applied.
MMS involves Global Navigation Satellite Systems (GNSS) and Inertial Measurement Units (IMU) to georeference point clouds. Their accuracy depends on the acquisition environment. In this study, the influence of the urban pattern is analysed in three zones with varied urban characteristics: different height buildings, open areas, and areas with a low and high level of urbanization.
To evaluate the efficiency of the proposed algorithms, three areas were chosen with varying urban patterns in Abu Dhabi. In these areas, 3D urban elements (light poles, street signs, etc) were automatically extracted using commercial software. The proposed algorithms were applied to the manholes and buildings.
The completeness and correctness ratio, and geometric accuracy were calculated for all urban elements in the three areas. The best success rates (>70%) were for light poles, street signs and road curbs, regardless of the height of the buildings. The worst rate was obtained for the same features in peri-urban areas, due to high vegetation. In contrast, the best results for trees were found in theses areas.
Our methodology demonstrates the great potential and efficiency of mobile LiDAR technology in updating basemaps; a process that is required to achieve standard accuracy in large scale maps.
The cost of the entire process and the time required for the proposed methodology was calculated and compared with the traditional method. It was found that mobile LiDAR could be a standard cost-efficient procedure for updating maps.La cartografía de referencia es la principal herramienta en planificación urbanística, y gestión de infraestructuras y edificios, al servicio de ciudadanos, empresas y administración. Por esta razón, debe estar actualizada y ser lo más precisa posible. Tradicionalmente, la cartografía se actualiza mediante fotogrametría aérea o levantamientos terrestres. No obstante, deben buscarse alternativas válidas para escalas grandes, porque no siempre es posible emplear estas técnicas debido a las limitaciones y retos actuales a los que se enfrenta la medición tradicional en algunas zonas del planeta, con meteorología extrema o restricciones de vuelo por la proximidad a la frontera con otros países. Esta tesis propone el uso del sistema Mobile Mapping System (MMS) para actualizar la cartografía urbana de referencia. La mayoría de los elementos pueden extraerse empleando software comercial o librerías abiertas, excepto los registros de servicios. Los elementos ocultos son otro de los inconvenientes encontrados en el proceso de creación o actualización de la cartografía, incluso si se dispone de capturas desde diferentes puntos de vista. El caso más común es el de las esquinas de edificios. Por ello, el principal objetivo de este estudio es establecer una metodología de extracción automática de los registros y completar las esquinas ocultas de los edificios para actualizar cartografía urbana. El algoritmo desarrollado para la detección y extracción de registros se basa en parámetros como el tiempo, la intensidad de la señal laser y la forma de los registros, mientras que para completar los edificios se emplea información adicional de imágenes satélite. Aprovechando el conocimiento del material y dimensión de los registros, en disposición de los gestores municipales, el algoritmo propuesto filtra y clasifica los puntos de acuerdo a los valores de intensidad. De aquellos clasificados como registros se calcula el mínimo rectángulo que los contiene (Minimum Bounding Rectangle) y finalmente se ajusta la forma y se dibuja. Las imágenes de satélite son empleadas para obtener automáticamente la huella de los edificios. Posteriormente, se importan las esquinas visibles de los edificios obtenidas desde la nube de puntos y se realiza el ajuste comparándolas con las obtenidas desde satélite. Para llevar a cabo este ajuste se han evaluado dos métodos, el primero de ellos considera las diferencias entre las coordenadas XY, desplazándose el promedio. En el segundo, se aplica una transformación Helmert2D. MMS emplea sistemas de navegación global por satélite (Global Navigation Satellite Systems, GNSS) e inerciales (Inertial Measurement Unit, IMU) para georreferenciar la nube de puntos. La precisión de estos sistemas de posicionamiento depende del entorno de adquisición. Por ello, en este estudio se han seleccionado tres áreas con distintas características urbanas (altura de edificios, nivel de urbanización y áreas abiertas) de Abu Dhabi con el fin de analizar su influencia, tanto en la captura, como en la extracción de los elementos. En el caso de farolas, señales viales, árboles y aceras se ha realizado con software comercial, y para registros y edificios con los algoritmos propuestos. Las ratios de corrección y completitud, y la precisión geométrica se han calculado en las diferentes áreas urbanas. Los mejores resultados se han conseguido para las farolas, señales y bordillos, independientemente de la altura de los edificios. La peor ratio se obtuvo para los mismos elementos en áreas peri-urbanas, debido a la vegetación. Resultados opuestos se han conseguido en la detección de árboles. El coste económico y en tiempo de la metodología propuesta resulta inferior al de métodos tradicionales. Lo cual demuestra el gran potencial y eficiencia de la tecnología LiDAR móvil para la actualización cartografía de referencia
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Marastoni, Diego. "Metodi matematici e statistici finalizzati al rilievo di precisione mediante SISTEMI MOBILE MAPPING SYSTEM." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amslaurea.unibo.it/333/.
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Reichenbacher, Tumasch. "Mobile cartography : adaptive visualisation of geographic information on mobile devices /." München : Verlag Dr. Hut, 2004. http://purl.fcla.edu/UF/lib/MobileCartography.pdf.
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Nováčková, Soňa. "Testování přesnosti mobilního mapovacího systému MOMAS." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225361.
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The aim of this thesis is to introduce the mobile mapping system MOMAS, which is owned by Geodis Brno, spol. s.r.o. and test the accuracy of the system. Perform data collection and processing of data in the workplace company Geodis. In addition, identical target points, determine their coordinates and compare them with the coordinates obtained MOMAS system. And finally processed statistically derived coordinate differences.
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Duque, Fredd. "Six DOF tracking system based on smartphones internal sensors for standalone mobile VR." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-260345.
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Nowadays mid-range smartphones have enough computational power to run simultaneous location and mapping (SLAM) algorithms that, together with their onboard inertial sensors makes them capable of position and rotation tracking. Based on this, Google and Apple have released their own respective software development kits (SDKs) that allow smartphones to run augmented reality applications using six degrees of freedom tracking. However, this same approach could be implemented to virtual reality head-mounted-display (HMD) based on smartphones, but current virtual reality SDKs only offer rotational tracking. In this study the positional tracking technology used for augmented reality mobile applications has been implemented in a virtual reality head-mounted-display only powered by a smartphone by combining virtual and augmented reality SDKs. Compatibility issues between SDKs have been faced to develop a working prototype. An objective and controlled measurement study has been conducted that included 34.200 measurements, to test the accuracy, precision and jitter tracking of the protype against the Oculus Rift, a dedicated virtual reality system. Results show that the developed prototype offers a decent tracking precision and accuracy in optimal conditions. It was concluded to be highly dependent on the camera view. Although, jitter presented the opposite behavior, being dependent to the device used but independent on the camera view. In its optimal conditions, user studies demonstrated that the prototype was capable of offering the same tracking performance feeling as the Oculus Rift although jitter was quite noticeable, and a common user complain. Further studies are proposed that can improve the tracking performance of the prototype by filtering jitter and using two or more cameras with a different angular to correlate feature points and obtain a wider view of the environment were the prototype is used.Idag har mellanklass-smartphones tillräckligt med beräkningskapacitet för att simultant köra lokalisering och kartläggnings(SLAM) algoritmer tillsammans med deras tröghetssensorer ombord, vilket gör att de kan positionera och rotera spårning. Baserat på det här så har Google och Apple släppt sina egna respektive programvaror (SDK) som gör att smartphones kan köra ökade realitetsapplikationer med sex graders frihetsspårning. Emellertid kan samma tillvägagångssätt implementeras till virtuell verklighet på en huvudmonterad display (HMD) baserat på smartphones, men nuvarande VR SDK erbjuder endast rotationsspårning. I denna studie så har positionell spårningsteknik som används för AR i mobila applikationer implementerats i ett VRheadset som endast drivs av en smartphone genom att kombinera VR och ARSDKs. Kompatibilitetsproblem mellan SDKs har resulterat i att utveckla en fungerande prototyp. En objektiv och kontrollerad mätstudie har genomförts som inkluderade 34.200 mätningar, för att testa noggrannheten, precision och jitterspårning av protyp mot Oculus Rift, ett dedikerat virtuellt verklighetssystem. Resultat visar att den utvecklade prototypen ger en anständig spårningsprecision och noggrannhet i optimala betingelser. Denna slutsats var mycket beroende av kameravy. Även om jitter presenterade det motsatta beteendet, beroende på vilken enhet som används men oberoende av kamerans vy. I sina optimala förhållanden visade användarstudier att prototypen kunde erbjuda samma spårningsförmåga som Oculus Rift, även om jitter var ganska märkbar, och en vanlig användares klagomål. Ytterligare studier föreslås som kan förbättra prototypens spårningsprestanda genom att filtrera jitter och använder två eller flera kameror med en annan vinkling till att korrelera funktionspunkter och få en bredare bild av miljön var prototypen används.
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Capucci, Laura. "Analisi di rilievi con mobile mapping system per lo sviluppo di un sistema informatizzato di gestione integrata delle pavimentazioni stradali." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2038/.
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Venený, Petr. "Detekce prostorových objektů v mračně bodů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-400180.
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The diploma thesis deals with processing of a point cloud that was collected via mobile mapping system. The first part sets a theoretical background, starting with mapping in general moving to mobile mapping systems and their particular parts. The practical part describes the whole process of data collecting, testing the automatic detection of spatial objects based on a point cloud and its visualisation. The results of the diploma thesis are GIS data layers and an evaluation of the process.
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Huang, Henry. "Bearing-only SLAM : a vision-based navigation system for autonomous robots." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/28599/1/Henry_Huang_Thesis.pdf.
Full textAbstract:
To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.
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Huang, Henry. "Bearing-only SLAM : a vision-based navigation system for autonomous robots." Queensland University of Technology, 2008. http://eprints.qut.edu.au/28599/.
Full textAbstract:
To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.
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Manda, David. "Mobilní mapování." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226350.
Full textAbstract:
The aim of this thesis is introduce the mobile mapping system IP-S2, which is using by company GEODIS BRNO, and perform data collection by this system. Measure the identical points, determine their coordinates and compare with coordinates obtained by mobile mapping system. The conclusion of this thesis is focused on testing the accuracy of the mobile mapping system.
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Nováková, Věra. "Vypracování metodik pro tvorbu informačního modelu budovy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-227099.
Full textAbstract:
This thesis is focused on creation of building information model (BIM) for existing buildings. The main objective of this work is to develop the methodology (workflow) for the creation of BIM model using selected geodetic methods, specifically for the modeling based on the existing documentation of the building, the modeling from the handheld distance meter and the modeling from point cloud acquired by the indoor mapping system. The aim of these workflows is to explore the suitability of these methods, to check the limits of each method and to point out the potential issues. Revit (version 2013 and 2014) was used as an authoring environment for creation of the models. Workflow for modeling based on the documentation of the building shows how to insert drawings into Revit and how to create a model based on these drawings. The workflow was developed based on experience with creation of model of an office building. The workflow for handheld laser distance meter describes how to work with rangefinder equipped with Bluetooth, which allows user to create a model onsite. The third part of this thesis deals with creation of BIM from pointcloud acquired by indoor mobile mapping system. The workflow describes data collection and point clouds processing directly in Revit using the ScanToBIM extension. The results of this work are methodical instructions for the methods described above and the comparison of these methods. Workflows contain recommended procedures and highlight common issues and mistakes. This should enable the readers of this thesis to choose the right method and avoid common mistakes.
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Hoffmannová, Lada. "Testování přesnosti mobilního laserového skenování." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-414306.
Full textAbstract:
Diploma thesis describes collecting of data by mobile mapping system Riegl VMX-450. Science centre AdMas was captured with mobile mapping system. For the purpose of testing the accuracy, a calibration field was constructed in AdMaS. Main part of the thesis deals with testing of the accuracy of point cloud. Calibration field's coordinates were obtained by adjustment of the geodetic network using the least squares adjustment. During the testing, the coordinates of the calibration field points determined by the adjustment of the geodetic network and the coordinates of the points determined from the point cloud were compared. Another part of the work deals with testing of the accuracy, when target's position is in different height levels.
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Biasutti, Pierre. "2D Image Processing Applied to 3D LiDAR Point Clouds." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0161/document.
Full textAbstract:
L'intérêt toujours grandissant pour les données cartographiques fiables, notamment en milieu urbain, a motivé le développement de systèmes de cartographie mobiles terrestres. Ces systèmes sont conçus pour l'acquisition de données de très haute précision, telles que des nuages de points LiDAR 3D et des images optiques. La multitude de données, ainsi que leur diversité, rendent complexe le traitement des données issues de ce type de systèmes. Cette thèse se place dans le contexte du traitement de l'image appliqué au nuages de points LiDAR 3D issus de ce type de système.Premièrement, nous nous intéressons à des images issues de la projection de nuages de points LiDAR dans des grilles de pixels 2D régulières. Ces projections créent généralement des images éparses, dans lesquelles l'information de certains pixels n'est pas connue. Nous proposons alors différentes méthodes pour des applications telles que la génération d'orthoimages haute résolution, l'imagerie RGB-D et l'estimation de la visibilité des points d'un nuage.De plus, nous proposons d'exploiter la topologie d'acquisition des capteurs LiDAR pour produire des images de faible résolution: les range-images. Ces images offrent une représentation efficace et canonique du nuage de points, tout en étant directement accessibles à partir du nuage de points. Nous montrons comment ces images peuvent être utilisées pour simplifier, voire améliorer, des méthodes pour le recalage multi-modal, la segmentation, la désoccultation et la détection 3DThe ever growing demand for reliable mapping data, especially in urban environments, has motivated the development of "close-range" Mobile Mapping Systems (MMS). These systems acquire high precision data, and in particular 3D LiDAR point clouds and optical images. The large amount of data, along with their diversity, make MMS data processing a very complex task. This thesis lies in the context of 2D image processing applied to 3D LiDAR point clouds acquired with MMS.First, we focus on the projection of the LiDAR point clouds onto 2D pixel grids to create images. Such projections are often sparse because some pixels do not carry any information. We use these projections for different applications such as high resolution orthoimage generation, RGB-D imaging and visibility estimation in point clouds.Moreover, we exploit the topology of LiDAR sensors in order to create low resolution images, named range-images. These images offer an efficient and canonical representation of the point cloud, while being directly accessible from the point cloud. We show how range-images can be used to simplify, and sometimes outperform, methods for multi-modal registration, segmentation, desocclusion and 3D detection
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Saad, Sawsan. "Conception et Optimisation Distribuée d’un Système d’Information des Services d’Aide à la Mobilité Urbaine Basé sur une Ontologie Flexible dans le Domaine de Transport." Thesis, Ecole centrale de Lille, 2010. http://www.theses.fr/2010ECLI0017/document.
Full textAbstract:
De nos jours, les informations liées au déplacement et à la mobilité dans un réseau de transport représentent sans aucun doute un potentiel important.Ces travaux visent à mettre en œuvre un Système d’Information de Service d’Aide à la Mobilité Urbaine (SISAMU).Le SISAMU doit pouvoir procéder par des processus de décomposition des requêtes simultanées en un ensemble de tâches indépendantes. Chaque tâche correspond à un service qui peut être proposé par plusieurs fournisseurs d’information en concurrence, avec différents coûts, temps de réponse et formats. Le SISAMU est lié à un Réseau informatique Etendu et distribué de Transport Multimodal (RETM) qui comporte plusieurs sources d’information hétérogènes des différents services proposés aux utilisateurs de transport. L’aspect dynamique, distribué et ouvert du problème, nous a conduits à adopter une modélisation multi-agent pour assurer au système une évolution continue et une flexibilité pragmatique. Pour ce faire, nous avons proposé d’automatiser la modélisation des services en utilisant la notion d’ontologie. Notre SISAMU prend en considération les éventuelles perturbations sur le RETM.Ansi, nous avons créé un protocole de négociation entre les agents. Le protocole de négociation proposé qui utilise l’ontologie de la cartographie se base sur un système de gestion des connaissances pour soutenir l'hétérogénéité sémantique. Nous avons détaillé l’Algorithme de Reconstruction Dynamique des Chemins des Agents (ARDyCA) qui est basé sur l’approche de l’ontologie cartographique. Finalement, les résultats présentés dans cette thèse justifient l’utilisation de l’ontologie flexible et son rôle dans le processus de négociationNowadays, information related on displacement and mobility in a transport network represents certainly a significant potential. So, this work aims to modeling, to optimize and to implement an Information System of Services to Aid the Urban Mobility (ISSAUM).The ISSAUM has firstly to decompose each set of simultaneous requests into a set of sub-requests called tasks. Each task corresponds to a service which can be proposed different by several information providers with different. An information provider which aims to propose some services through our ISSAUM has to register its ontology. Indeed, ISSAUM is related to an Extended and distributed Transport Multimodal Network (ETMN) which contains several heterogeneous data sources. The dynamic and distributed aspects of the problem incite us to adopt a multi-agent approach to ensure a continual evolution and a pragmatic flexibility of the system. So, we proposed to automate the modeling of services by using ontology idea. Our ISSAUM takes into account possible disturbance through the ETMN. In order to satisfy user requests, we developed a negotiation protocol between our system agents. The proposed ontology mapping negotiation model based on the knowledge management system for supporting the semantic heterogeneity and it organized as follow: Negotiation Layer (NL), the Semantic Layer (SEL), and the Knowledge Management Systems Layer(KMSL).We detailed also the reassignment process by using Dynamic Reassigned Tasks (DRT) algorithm supporting by ontology mapping approach. Finally, the experimental results presented in this thesis, justify the using of the ontology solution in our system and its role in the negotiation process
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Ambrus, Rares. "Unsupervised construction of 4D semantic maps in a long-term autonomy scenario." Doctoral thesis, KTH, Centrum för Autonoma System, CAS, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215323.
Full textAbstract:
Robots are operating for longer times and collecting much more data than just a few years ago. In this setting we are interested in exploring ways of modeling the environment, segmenting out areas of interest and keeping track of the segmentations over time, with the purpose of building 4D models (i.e. space and time) of the relevant parts of the environment. Our approach relies on repeatedly observing the environment and creating local maps at specific locations. The first question we address is how to choose where to build these local maps. Traditionally, an operator defines a set of waypoints on a pre-built map of the environment which the robot visits autonomously. Instead, we propose a method to automatically extract semantically meaningful regions from a point cloud representation of the environment. The resulting segmentation is purely geometric, and in the context of mobile robots operating in human environments, the semantic label associated with each segment (i.e. kitchen, office) can be of interest for a variety of applications. We therefore also look at how to obtain per-pixel semantic labels given the geometric segmentation, by fusing probabilistic distributions over scene and object types in a Conditional Random Field. For most robotic systems, the elements of interest in the environment are the ones which exhibit some dynamic properties (such as people, chairs, cups, etc.), and the ability to detect and segment such elements provides a very useful initial segmentation of the scene. We propose a method to iteratively build a static map from observations of the same scene acquired at different points in time. Dynamic elements are obtained by computing the difference between the static map and new observations. We address the problem of clustering together dynamic elements which correspond to the same physical object, observed at different points in time and in significantly different circumstances. To address some of the inherent limitations in the sensors used, we autonomously plan, navigate around and obtain additional views of the segmented dynamic elements. We look at methods of fusing the additional data and we show that both a combined point cloud model and a fused mesh representation can be used to more robustly recognize the dynamic object in future observations. In the case of the mesh representation, we also show how a Convolutional Neural Network can be trained for recognition by using mesh renderings. Finally, we present a number of methods to analyse the data acquired by the mobile robot autonomously and over extended time periods. First, we look at how the dynamic segmentations can be used to derive a probabilistic prior which can be used in the mapping process to further improve and reinforce the segmentation accuracy. We also investigate how to leverage spatial-temporal constraints in order to cluster dynamic elements observed at different points in time and under different circumstances. We show that by making a few simple assumptions we can increase the clustering accuracy even when the object appearance varies significantly between observations. The result of the clustering is a spatial-temporal footprint of the dynamic object, defining an area where the object is likely to be observed spatially as well as a set of time stamps corresponding to when the object was previously observed. Using this data, predictive models can be created and used to infer future times when the object is more likely to be observed. In an object search scenario, this model can be used to decrease the search time when looking for specific objects.QC 20171009
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Chen, Shu-Ching, and 陳淑菁. "A GPRS/UMTS/WLAN MMS System for Supporting Mobile E-learning." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/02297552405848650524.
Full textAbstract:
碩士元智大學
資訊工程學系
94
Technological trends strongly favor the spread of mobile e-learning (M-learning). However, the existing full-coverage mobile networks, such as General Packet Radio Service (GPRS) and Universal Mobile Telecommunication System (UMTS), are not able to effectively support content-rich multimedia transmission since the practical data rates offered are limited to 50/300 kbps. In parallel with the full-coverage GPRS/UMTS networks, Wireless Local Area Network (WLAN) provides high-speed transmission services with actual data rates around 30 Mbps in a short-range local mobility environment. By integrating the sophisticated mobility management mechanism provided by GPRS/UMTS and the broadband transmission service provided by WLAN, we design and develop a GPRS/UMTS/WLAN multimedia messaging service (MMS) system, called GWMMS system. The GWMMS system provides instant messaging notification, content-rich messaging access, convergent, and especially, cheap messaging service. On the basis of the GWMMS system, we propose a GWMMS M-learning prototype. With the GWMMS M-learning prototype, we demonstrate a field-based learning system.
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Chung, Wen-Tsung, and 鐘文聰. "Studies of Simultaneous Localization and Mapping Using Mobile Sensing System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/26389673920873023097.
Full textAbstract:
碩士國立高雄第一科技大學
電腦與通訊工程研究所
101
Simultaneous localization and mapping (SLAM) is considered a key technology for mobile sensing devices to perform autonomous operations in an unknown environment. In general cases, GPS data or the establishment of specific known landmark positions can be used to infer the position of the mobile sensing devices and mapping. However, when the mobile sensing devices must be positioned in an unknown environment and the map of the environment must be produced, the task of positioning and mapping becomes more complicated. SLAM technique is one solution to the problem. The current stationary environmental characteristics in unknown environment through sensors can be used to complete the positioning and mapping. For mobile sensing devices in SLAM problem, there is no analytic solution in recursive Bayesian estimation algorithms. Therefore, extended Kalman filters are usually used to achieve recursive Bayesian estimation prediction and correction. Mobile sensing devices perform prediction and correction through the extended Kalman filter based SLAM algorithms by using known vehicle model and observation model. Since the accuracy of positioning and landmark location estimation will affect the overall mapping information, studies on the factors that affect the accuracy of SLAM is essential. In the thesis, different environmental and parameter settings are simulated to show how the performance of self-localization and mapping are affected by sensing range of the sensors, path planning schemes, number of landmarks, and the deployment schemes of landmarks. Simulation examples and results are discussed and analyzed.
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Chen, Po Chou, and 陳柏州. "The Study Of Mobile Mapping System Used In Slope Investigation." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/79770697976424606026.
Full textAbstract:
碩士國防大學理工學院
空間科學碩士班
100
Event site, type and scale are always the key issues to be realized while investigating disaster prevention and rescue. Slope investigation, for example, finding the precise absolute coordinates of rocks or mud is not only time and labor consuming but also not necessary. Mobile mapping system with high mobility, fast information acquisition and non-contact measurement can ensure work safety while investigating spatial information in unreachable or high-risk area. Therefore, mobile mapping system is quite suitable for small area slope spatial information investigation. Traditional position and orientation systems are not applied to obtain spatial absolute coordinates in this study, while two calibration non-metric cameras with hyperfocal distance setting installed on car roof are used to get the slope stereo pairs and PhotoModeler Scanner 6.2 software is used to establish its relative cloud model and known length spatial control lines are used to determine the model scale. Therefore, without positioning and orientation error impacts of GPS and INS, mobile mapping system can not only reduce the cost but also improve the relative precising of point cloud model and provide reliable slope spatial information. The experimental results shows while single stereo pair with known length spatial control lines to determinate the model scale, within 30m shooting distance, the distance measurement RMSE is about ±1.40cm in X direction and ±2.15cm in Y direction. In experimental area, 4 stereo pairs are used within 40m shooting distance in the case of steep slope, the distance difference between check points is less than 16cm. It is less than 8cm in gradual slope, while 5 pairs are used. The results suggest that this method has the potential to replace high cost mobile mapping system or terrestrial LiDAR while performing spatial information investigation in small slope area.
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Liao, Yi-Jin, and 廖宜津. "Simultaneous Localization and Mapping Based Auto-recharge System for Mobile Robot." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/m79ypx.
Full textAbstract:
碩士國立雲林科技大學
電機工程系
105
This study develops an Automatic Guided Vehicle (AGV) based on simultaneous localization and mapping (SLAM) technology. The laser measurement sensor is basically equipped, that is used to scan the surrounding environment, then construct a map of the current situation. Also the AGV has auto-recharge function. When the power of the AGV is under the threshold. The AGV uses the infrared sensor to find the location of the charging station, and executes the charging process to ensure the enough power that can provide following tasks. To achieve the positioning of the charging station, 86Duino One is used to determine the infrared sensing results and control the movement of mecanum-wheel platform. 86Duino One communicates with the computer through the RS232 communication interface, and receives the information of the laser measurement sensor. After having enough power, the car can use the resulting map to carry out the path planning and its related actions.
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Yi-HsiangChang and 張詒翔. "A Feasibility Study of Using e-GPS for Mobile Mapping System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/01608335448447469356.
Full textAbstract:
碩士國立成功大學
測量及空間資訊學系
102
Mobile Mapping System (MMS) has been developed quite maturely. MMS is equipped with positioning and orientation systems, including a variety of sensors. One of the sensors is Global Position System (GPS). It has many advantages, such as high precision, fast and convenient positioning. Most of GPS data processing for MMS is post-processing. Post-processing can maintain high accuracy, but it cannot position in real-time. National Land Surveying and Mapping Center has constructed a network real-time kinematic (RTK) system named e-GPS. The e-GPS brings faster and more convenient positioning results. This research aims at using e-GPS for MMS, but the feasibility of e-GPS for MMS is still unclear, so we attempt to compare post-processing and real-time processing. Because environment condition will significantly affect the position accuracy of GPS, we tested MMS in three different types of environment conditions. The results show that real-time processing uses more strict standards for producing virtual reference station (VRS) observations. In the suburbs area, the results of real-time processing and post processing is very similar. In the urban, part of satellites single usually were masked. In this situation, the result of post processing is better than the result of real-time processing. But, because of the observation of satellite were not enough to calculate, two methods were both getting bad result.
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Su, chiun shiang, and 蘇群翔. "Localization / Mapping and Independent Motion Control System for a Mobile Robot." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/59280978979654823428.
Full textAbstract:
碩士淡江大學
機械與機電工程學系碩士班
98
The objective of this thesis is to design a robot to have independent motion behaviors and obstacle avoidance function. The robot is also able to make the SLAM(Simultaneous Localization And Mapping) at the unknown environment. First, the software of the robot platform is designed to define the robot position by the motor encoders. Then , the obstacle avoidance controller is developed by two input variables (angular and distance errors) of the fuzzy theory. A laser ranger finder is linked to the segway by the TCP/IP (Transmission Control Protocol / Internet Protocol). The environmental information of laser ranger finder is the important input variables of the obstacle avoidance controller. The simulated results of this system is implemented by the Matlab software. After that, the simulated program is transformed into VC++ MFC program to demonstrate the actual motion behavior of this robot system. The calculation algorithms of ICP(Iterative Closest Point) is applied to check the position error of the environmental data to obtain the estimated position of the laser range finder. The estimated position data are used to calculated the final function of SLAM. Finally, both the simulated and experimental results show that the system work very well.
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Tsai, Li-Yun, and 蔡立筠. "3D modeling of interior space using smartphone-based mobile mapping system." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3f9ug3.
Full textAbstract:
碩士國立政治大學
地政學系
106
Due to the significant improvement of wearable devices, virtual reality (VR) and augmented reality (AR) applications have been developed rapidly. To support various VR and AR applications, three-dimensional models are essential tools. Moreover, a flexible, efficient and real-time processing to generate 3D models is highly required. To achieve this, smart phone nowadays equipping with GNSS receiver, MEMS-based IMU, excellent computational capabilities and high resolution camera becomes a possible solution for purpose of low-cost and accessible mobile mapping system (MMS). In this study we developed a smartphone application aiming for interior space model reconstruction. With the technique of monocular simultaneous localization and mapping (Mono SLAM) and data collected through IMU in smartphone, users are able to reconstruct, localize and visualize the 3D model of interior space. In additional, by using the system we designed in the application, users can interactively guide the reconstruction process to resolve the structural ambiguities and errors during the acquisition with MonoSLAM. The resultant 3D model can be displayed in near real-time.
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Chang, Po-Wei, and 張柏偉. "Software Framework for Data Processing in Mobile Mapping System and Its Application." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/47114798284500700074.
Full textAbstract:
碩士國立臺灣大學
土木工程學研究所
103
The precision of spatial data acquired by vehicle-based Mobile Mapping System (MMS) depends highly on the precision of the positioning equipment. After Global Positioning System (GPS) is not able to receive enough satellite signals for a while, the error propagation in positioning of IMU will affect the precision of spatial data. There are many adjustment models aiming to reduce the error, but there are few software tools that are flexible enough to support the operation of adjustment. In this thesis, a software framework is developed for data processing in MMS, called ntuMMF (NTU Mobile Mapping Framework). The architecture of ntuMMF is pipes and filters. ntuMMF consists of six major components: source, reader, filter, sink, writer and mapper. The processing pipeline is a composite of these components. These components have the same interface, so the new processing pipeline can be easily created by adding a new component. In addition, ntuMMF formulates the operating procedure of these components to make sure the processing pipeline can work seamlessly. A toolkit for data processing in MMS, called MMTK (Mobile Mapping Toolkit), is developed based on ntuMMF. MMTK supports many common files’ formats in MMS; it also provides the basic data processing functions. Some templates are provided for developers to implement the algorithm rapidly. Three different examples are used to demonstrate the flexibility of the proposed framework and toolkit. The first example shows the flexibility of the combination of the pipeline. Although there are only three components in the processing pipeline, the new processing pipeline can be created by replacing a component with different functions. As a result, a three-component pipeline can solve most of the requirements from the first example. The second example shows the flexibility of the operation of the pipeline. The request-intensive service in the example can be implemented by calling the trigger function of the pipeline. Because the pipeline can work partially, the time of handling user’s requests can be very short. The third example not only shows the flexibility of the operation of the pipeline as the second example, but also demonstrates the versatility of ntuMMF. The type of data in the third example is different from the data in the above examples, but the data processing procedures remain identical. The contribution of ntuMMF is twofold. First, by encapsulating the data processing procedure, the process flow becomes more flexible for reuse. Second, the versatility of the framework unifies the procedure of data processing in MMS, and it demonstrates the development procedure step by step.
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Shih, Kai-lun, and 施凱倫. "Using Mobile Mapping System to Extract Road Marking for Road Model Reconstruction." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/33818031747052284434.
Full textAbstract:
碩士國立中央大學
土木工程學系
102
The technology of Mobile Mapping System (MMS) is advancing rapidly. MMS can acquire image sequences and position data more efficiently and effectively. Thus, the integration of MMS and remote sensing data is an important task in geospatial technologies for various applications, such as road model reconstruction, building up three dimensional attribute databases, and so on. The primary objective of this research is to reconstruct the detailed road model and build up attribute database. Focus is placed on extracting and recognizing road markings, especially direction markings, automatically from MMS images. The proposed scheme consists of four major parts: (1) region of interesting (ROI) extraction, (2) ROI filtering, (3) road markings recognition, (4) model integration. In the ROI extraction, the mean-shift based image segmentation is employed for automatically extracting ROI and solving the shadow area resulted from trees or cars. Secondly, in order to extract the features of ROI, Harris corner detector is utilized to detect the vertexes from ROI. Subsequently, three dimensional coordinates of vertexes from ROI are calculated using collinearity condition equations. In the third part, a proposed road markings recognition method is used to recognize ROI with road marking templates. Finally, recognized road markings and attribute information are placed to corresponding locations of Level of detail (LOD) 2 road model based on the calculated coordinates. Experimental results demonstrate that ROI extraction is more efficient using the developed image segmentation techniques. Meanwhile the proposed algorithm can improve several ROI features of road markings recognition. In addition, the experimental results prove that using the proposed algorithms, integrating MMS data and other geo-information can reconstruct highly detailed road models with attribute database.
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Wu, Kenyi, and 吳建億. "Utilization of Object Space Conditions for Camera Calibration of A Mobile Mapping System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/12729249932979058619.
Full textAbstract:
碩士國立成功大學
測量及空間資訊學系碩博士班
97
In this thesis, the camera calibration for a mobile mapping system (MMS) is to determine the interior orientation parameters, field of systematic bias vectors of image point positions, and the relative orientation of arbitrary two cameras on the MMS. Image coordinates of image points and diverse object space conditions are utilized to evaluate the aforementioned parameters without the need on calibration field. This thesis utilizes four methods for the calibration of cameras on a MMS in which the calibration is done anywhere the MMS stays. The object space conditions such as the known distances, angles or coordinate differences are integrated with bundle adjustment to estimate the parameters of all cameras on a MMS. Test results show that the proposed object-space-condition method is applicable for calibrating cameras of a MMS. The interior orientation parameters determined by three methods - three-vanishing-point method, two-vanishing-point method, and three-coordinate-axis method - are the same if they use the same set of image points inclusive of vanishing points and end points of vanishing lines. The object-space-condition method integrates different kinds of conditions (such as known lengths, angles, coordinate differences, coordinates, object heights as well as the perpendicular and parallel conditions) in object space to estimate the camera parameters by using the images taken by cameras on a mobile mapping system. The object space conditions adopted in all tests include known distances, coordinate differences, the parallel and perpendicular conditions, and are used to evaluate the precision of interior orientation elements and exterior orientation parameters defined in a local 3D coordinate system, which are about 0.008~0.010mm、 1~13cm、 0.052~0.211 degrees, respectively. Keyword: Camera Calibration, Vanishing Points, Three-Axes Conditions in Object Space, Bundle Adjustment
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Sen, Wei Ching, and 魏清森. "Mobile Mapping System in Application of 3 Dimensional Modeling on the Small Object." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/59775852666613583319.
Full textAbstract:
碩士國防大學理工學院
空間科學碩士班
97
With the advancement of surveying and mapping technology, the mobile positioning and spatial data surveying techniques are established. These techniques are also known as the Mobile Mapping System (MMS) which has a design concept of automatically surveying spatial information in a prompt manner. Therefore, the needs for the real-time and integrity acquisition of spatial data can be accomplished. Besides, MMS is extensively applied in different fields. Due to the maturity of presence computer graphics techniques, the concept of coordinate transformation can be utilized for the construction of object in the reality world into the three-dimensional model. Subsequently, the model can be displayed. Moreover, the expression method which adopts real-time and dynamic visualization enables the transmission of information in bulk within a short period of time. Simultaneously, operational and computational analyses are implemented in a more instinctive approach. The sources for acquisition of three-dimensional modeling information determine the content, format, precision and object model, and object modeling method of the information accessed. Hence, there are diverse purposes in the application. This research employs MMS as the acquisition method for modeling data by including two digital cameras and three GPS receivers as the hardware architecture. Digital camera will photograph the object’s images and construct modeling on three-dimensional small object through close-range photogrammetry. In addition, the textural images are projected on the surface of the three-dimensional model, which form the realistic simulation of three-dimensional models. On the other hand, the GPS antenna receives satellite signal and converts the coordinate information into parameters of absolute orientation. After the recalculation of feature point coordinate, the model coordinates are converted into object space coordinate system. In this research, the Weaponry Garden located at Chung Cheng Institute of Technology, National Defense University is selected as the small object in modeling. After the object modeling, the relative precision is approximately between 1.4 cm and 6.4 cm. This research is expected to transmit spatial information in a more instinctive approach to the users via the three-dimensional modeling of actual object.
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Shr, Bo-Rung, and 施柏榮. "The Design And Test Of The Position Module For A Mobile Mapping System." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/10807700927108917687.
Full textAbstract:
碩士國立成功大學
航空太空工程學系碩博士班
93
The mobile mapping system (MMS) has been used successfully in road inventory for many years. The price of current MMS is relative high mainly due to high cost components in the system (e.g. INS, large CCD chips, or laser scanner). In addition, image data processing is the bottleneck for MMS. This research intends to replace the CCD chips or laser scanner with a cheaper laser measurement unit to build up a new cost-effective system. The new system is supplemented by a CCD camera in addition to GPS and INS, which is used for position and attitude information. The system is applied to monitor the surroundings out of the car and taking pictures of the aimed object in this research. Besides, the system combines the GPS information with a digital map to implement real time car navigation. The overall positioning error of the new system used in this study is around one meter. Comparing with current MMS, the accuracy is still good enough. Considering the price and the functions of the system, the system is economical and useful.
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Santiago, Carlo, and 尚馬聖. "Active Air Filtering and PM2.5 Real-Time Mapping System by Autonomous Mobile Robot." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7phx3y.
Full textAbstract:
碩士中原大學
電機工程研究所
106
The main purpose of this research is to design an autonomous mobile robot that can navigate around an indoor environment to provide information about the particulate matter 2.5 (PM¬2.5) concentration on the environment. Also, the mobile robot is equipped with an air filtering device that would operate whenever there is high concentration of the particulate matter. Moreover, the robot would provide a map of the concentricity of particulate matter inside the indoor environment which would give the operators about ideas where are the ideal places or the hazardous places with high concentration of PM2.5. The mobile robot also has a capability to navigate around and filter the air intelligently to decrease the battery consumption. The map of the concentration of PM2.5 will be displayed on the remote computer that controls the operation of the autonomous mobile robot automatically. As a result, the system is fully autonomous and the requirement of having a human operator to avoid the hazardous effects of the particulate matter to humans is no longer required.
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Wang, Feng-Liang, and 王豐良. "A Study of Vehicle-Based Mobile Mapping System Using GPS and Non-Metric Camera." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/78622338471443009138.
Full textAbstract:
碩士國防大學中正理工學院
軍事工程研究所
96
With the development of surveying and mapping technology, realtime moving platforms of surveying and geospatial information collection, referred to as Mobile Mapping System (MMS), were built. In the researches about MMS at present, acquisition of position and orientation of system use the way that Inertial Navigation System (INS) combined with GPS, acquisition of the distance and image use CCD cameras or 3D scanner. Because cost of high-accuracy INS and 3D scanner are expensive, so the construction of MMS is with high costs, and if adopt low cost of INS, it can't meet the precision demand that the system measure. This research develop the MMS that combines three GPS receivers and two digital cameras. The system is used to set up Image Matching in order to reduce the spending of manpower and cost for acquisition of geospatial information. In this studying, observations from three GPS receivers at the same time. Were used to calculate the precision of position the result is 44cm when using DGPS, another using OTF is 1.2cm and using of coordinates to calculate the rotatory angle of three axles up to 0.6∘. The proportionate relationships of the distance between the objects and interval of cameras influence the precision of measurement, in a case that the interval of cameras is 1m, the distance between the objects is 20m and 30m with the precision difference between 20cm and 70cm. In simulation moving tested, that deleted the points of distance between the objects is greater than 30m after, the plane precision reaches 15cm, height precision reaches 60cm, precision obviously superior to MMS that combine GPS and low precision INS. In the road area move tested, the camera shooting time and GPS receiving time that difference is about 0.2 seconds, make position measurement error nearly 2m, and improve measurement precision of MMS, with the technology and method of time moving ahead simultaneously. MMS can be used in collection of GIS data, for instance, road inventory, natural resources inventory, cadastral survey, measurement after the natural calamity, etc. More traditional measurement method, more accurate, more economic, have easier renewing data.
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Cian-YouJhou and 周千又. "Positioning Improvement of Mobile Mapping System in Urban Area by Bundle Adjustment and Shadow Location Estimation." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/t4uhqx.
Full textAbstract:
碩士國立成功大學
測量及空間資訊學系
106
Mobile mapping system (MMS) is a new way and cost-efficient technique for acquiring three-dimensional spatial information in engineering like highways, urban streets, etc. Conventionally, the exterior orientation parameters (EOPs) of cameras on an MMS are calculated through direct geo-referencing (DG) by combining Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS). The results of MMS are processed by EOPs and space intersections. Nevertheless, the positioning accuracy by such way is limited by the quality of GNSS receivers and inertial measurement units (IMUs). In the research, the methods with bundle adjustment and shadow location estimation are adopted for positioning precision improvement. The utilization of bundle adjustment can elevate the number of redundancies to improve the precision and reliability of results and correct the EOPs of cameras to avoid the blunders or systematic errors from GNSS receivers and IMU’s measurements. On the other hand, the algorithm of shadow location estimation helps deal with poor performance of GNSS positioning in urban canyons to improve the precision of user’s position in cross-street direction. Results of the research show that the algorithm of bundle adjustment is the most efficient way to increase the accuracy of the MMS’s result. Rather than traditional way that conduct space intersections without shadow location estimation, the algorithms of shadow location estimation and the space intersections significantly improve the accuracy of the MMS’s positioning results by 33% based on the research. Additionally, using the algorithms of shadow location estimation and bundle adjustment significantly improve the accuracy of MMS’s positioning results on the level of 11%.
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Leung, Keith Yu Kit. "Cooperative Localization and Mapping in Sparsely-communicating Robot Networks." Thesis, 2012. http://hdl.handle.net/1807/32809.
Full textAbstract:
This thesis examines the use of multiple robots in cooperative simultaneous localization and mapping (SLAM), where each robot must estimate the poses of all robots in the team, along with the positions of all known landmarks. The robot team must operate under the condition that the communication network between robots is never guaranteed to be fully connected. Under this condition, a novel algorithm is derived that allows each robot to obtain the centralized-equivalent estimate in a decentralized manner, whenever possible. The algorithm is then extended to a decentralized and distributed approach where robots share the computational burden in considering different data association hypotheses in generating the centralized-equivalent consensus estimate.
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Resende, Yoann dos Santos. "Road Event Mapping Method for Mobile Devices with Cloud Computing based Technologies." Master's thesis, 2020. http://hdl.handle.net/10400.6/10819.
Full textAbstract:
Among other features, the road condition influences safety and driving comfort.
Driving styles are somewhat related to the road profile, which leads to the need for a
monitoring model to detect and signal damaged road segments and danger zones.
Some methods were developed to collect and format the data of road infrastructures, in
order to estimate the quality of the roads, based on the data collection from a mobile
phone’s sensors placed inside a vehicle and on the feeding of artificial intelligence
classification models. However, these methods do not provide instant feedback to the
driver in the vehicle nor checks driving styles and current road condition.
This work aimed to develop a system capable of detecting events on the road from the
driver’s point of view (this research being limited to breaking and acceleration events),
on different types of road pavements, using a machine learning supervised
classification method that can be used in the future in a connected architecture to alert
drivers of the dangers of the road ahead and therefore help increase road safety.Esta dissertação descreve a investigação realizada para identificar problemas que podemos encontrar na estrada como travagens ou acelerações súbitas, buracos na estrada ou lombas, usando equipamentos. Para a abordagem deste estudo foi necessário desenvolver uma aplicação para recolha de dados de acelerómetro e GPS recorrendo a um smartphone colocado dentro de um carro. Apos a recolha, os dados foram tratados e analisados por um modelo de inteligência artificial que identifica os eventos recolhidos pela aplicação. Se os resultados obtidos forem bons, será possível o desenvolvimento de um sistema de controlo do estado das estradas que poderá ser utilizado de forma pervasiva.
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(6843914), Radhika Ravi. "Interactive Environment For The Calibration And Visualization Of Multi-sensor Mobile Mapping Systems." Thesis, 2019.
Find full textAbstract:
LiDAR units onboard airborne and terrestrial platforms have been established as a proven technology for the acquisition of dense point clouds for a wide range of applications, such as digital building model generation, transportation corridor monitoring, precision agriculture, and infrastructure monitoring. Furthermore, integrating such systems with one or more cameras would allow forward and backward projection between imagery and LiDAR data, thus facilitating several high-level data processing activities such as reliable feature extraction and colorization of point clouds. However, the attainment of the full 3D point positioning potential of such systems is contingent on an accurate calibration of the mobile mapping unit as a whole.
This research aims at proposing a calibration procedure for terrestrial multi-unit LiDAR systems to directly estimate the mounting parameters relating several spinning multi-beam laser scanners to the onboard GNSS/INS unit in order to derive point clouds with high positional accuracy. To ensure the accuracy of the estimated mounting parameters, an optimal configuration of target primitives and drive-runs is determined by analyzing the potential impact of bias in mounting parameters of a LiDAR unit on the resultant point cloud for different orientations of target primitives and different drive-run scenarios. This impact is also verified experimentally by simulating a bias in each mounting parameter separately. Next, the optimal configuration is used within an experimental setup to evaluate the performance of the proposed calibration procedure. Then, this proposed multi-unit LiDAR system calibration strategy is extended for multi-LiDAR multi-camera systems in order to allow a simultaneous estimation of the mounting parameters relating the different laser scanners as well as cameras to the onboard GNSS/INS unit. Such a calibration improves the registration accuracy of point clouds derived from LiDAR data and imagery, along with their accuracy with respect to the ground truth. Finally, in order to qualitatively evaluate the calibration results for a generic mobile mapping system and allow the visualization of point clouds, imagery data, and their registration quality, an interface denoted as Image-LiDAR Interactive Visualization Environment (I-LIVE) is developed. Apart from its visualization functions (such as 3D point cloud manipulation and image display/navigation), I-LIVE mainly serves as a tool for the quality control of GNSS/INS-derived trajectory and LiDAR-camera system calibration.
The proposed multi-sensor system calibration procedures are experimentally evaluated by calibrating several mobile mapping platforms with varying number of LiDAR units and cameras. For all cases, the system calibration is seen to attain accuracies better than the ones expected based on the specifications of the involved hardware components, i.e., the LiDAR units, cameras, and GNSS/INS units.
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Yu-HuaLi and 李育華. "The Calibration Methodology of a Land Vehicle Mobile Mapping System and the Performance Analysis of the Direct Geo-referencing." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/64990406186314151564.
Full textAbstract:
碩士國立成功大學
測量及空間資訊學系碩博士班
98
Since INS is applied in civil applications, its related developments increase as time goes by. The mobile mapping system is one of the most important civil applicaiotns of INS/GPS integrated systems because of its rapidly direct geo-referencing capability which is useful in Geospatial Information acquisition for Taiwan, a small island with high population. In this study, a low cost INS/GPS integrated POS, was developed and applied to provide the positional and orientation information seamlessly. In addition, the Meinberg GPS170PCI timing board was applied to synchronize measurements provided by those sensors. For system calibration, a high-accuracy ground control field was established by means of the ground survey. The measurements collected by the proposed system from the control field were added to the bundle adjustment procedure to solve the lever-arm and boresight angles between those image sensors. Based on the parameters obtained after calibration, the proposed system could perform direct geo-referencing tasks. This study describes the architecture of the proposed system and the establishment of the control field. Then a two-step approach with some strategies are proposed to conduct system calibration. Finally, the system test, error analysis, and the results of system calibration are presented. The results of the experiment depict that the accuracy of direct geo-referencing capability in term of the positioning accuracy of the proposed is less than 15cm(HPE) and 28cm (3D). The analysis proves the stability of proposed system is high, and the applications in the disaster assessment or the highway inventory investigation are also feasible. While the maturity of related technology becomes higher, the system can provide more contribution in the future.
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(8333136), Mohammed D. Aldosari. "Mobile LiDAR for Monitoring MSE Walls with Smooth and Textured Precast Concrete Panels." Thesis, 2020.
Find full textAbstract:
Mechanically Stabilized Earth (MSE) walls retain soil on steep, unstable slopes with crest loads. Over the last decade, they are becoming quite popular due to their low cost-to-benefit ratio, design flexibility, and ease of construction. Like any civil infrastructure, MSE walls need to be continuously monitored according to transportation asset management criteria during and after the construction stage to ensure that their expected serviceability measures are met and to detect design and/or construction issues, which could lead to structural failure. Current approaches for monitoring MSE walls are mostly qualitative (e.g., visual inspection or examination). Besides being time consuming, visual inspection might have inconsistencies due to human subjectivity. Other monitoring approaches are based on using total station, geotechnical field instrumentations, and/or Static Terrestrial Laser Scanning (TLS). These instruments are capable of providing highly accurate, reliable performance measures. However, the underlying data acquisition and processing strategies are time-consuming and are not scalable. This research focuses on a comprehensive strategy using a Mobile LiDAR Mapping System (MLS) for the acquisition and processing of point clouds covering the MSE wall. The strategy produces standard serviceability measures, as defined by the American Association of State Highway and Transportation Officials (AASHTO) – e.g., longitudinal and transversal angular distortions. It also delivers a set of recently developed measures (e.g., out-of-plane offsets and 3D position/orientation deviations for individual panels constituting the MSE wall). Moreover, it is also capable of handling MSE walls with smooth or textured panels with the latter being the focus of this research due to its more challenging nature. For this study, an ultra-high-accuracy wheel-based MLS has been developed to efficiently acquire reliable data conducive to the development of the standard and new serviceability measures. To illustrate the feasibility of the proposed acquisition/processing strategy, two case studies in this research have been conducted with the first one focusing on the comparative performance of static and mobile LiDAR in terms of the agreement of the derived serviceability measures. The second case study aims at illustrating the feasibility of the proposed strategy in handling large textured MSE walls. Results from both case studies confirm the potential of using MLS for efficient, economic, and reliable monitoring of MSE walls.
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(10233353), Behrokh Nazeri. "Evaluation of Multi-Platform LiDAR-Based Leaf Area Index Estimates Over Row Crops." Thesis, 2021.
Find full textAbstract:
Leaf Area Index (LAI) is an important variable for both for characterizing plant canopy and as an input to many crop models. It is a dimensionless quantity broadly defined as the total one-sided leaf area per unit ground area, and is estimated over agriculture row crops by both direct and indirect methods. Direct methods, which involve destructive sampling, are laborious and time-consuming, while indirect methods such as remote sensing-based approaches have multiple sources of uncertainty. LiDAR (Light Detection and Ranging) remotely sensed data acquired from manned aircraft and UAVs’ have been investigated to estimate LAI based on physical/geometric features such as canopy gap fraction. High-resolution point cloud data acquired with a laser scanner from any platform, including terrestrial laser scanning and mobile mapping systems, contain random noise and outliers. Therefore, outlier detection in LiDAR data is often useful prior to analysis. Applications in agriculture are particularly challenging, as there is typically no prior knowledge of the statistical distribution of points, description of plant complexity, and local point densities, which are crop dependent. This dissertation first explores the effectiveness of using LiDAR data to estimate LAI for row crop plants at multiple times during the growing season from both a wheeled vehicle and an Unmanned Aerial Vehicle (UAV). Linear and nonlinear regression models are investigated for prediction utilizing statistical and plant structure-based features extracted from the LiDAR point cloud data and ground reference obtained from an in-field plant canopy analyzer and leaf area derived from destructive sampling. LAI estimates obtained from support vector regression (SVR) models with a radial basis function (RBF) kernel developed using the wheel-based LiDAR system and UAVs are promising, based on the value of the coefficient of determination (R2) and root mean squared error (RMSE) of the residuals.
This dissertation also investigates approaches to minimize the impact of outliers on discrete return LiDAR acquired over crops, and specifically for sorghum and maize breeding experiments, by an unmanned aerial vehicle (UAV) and a wheel-based ground platform. Two methods are explored to detect and remove the outliers from the plant datasets. The first is based on surface fitting to noisy point cloud data based on normal and curvature estimation in a local neighborhood. The second utilizes the deep learning framework PointCleanNet. Both methods are applied to individual plants and field-based datasets. To evaluate the method, an F-score and LAI are calculated both before and after outlier removal for both scenarios. Results indicate that the deep learning method for outlier detection is more robust to changes in point densities, level of noise, and shapes. Also, the predicted LAI was improved for the wheel-based vehicle data based on the R2 value and RMSE of residuals.
The quality of the extracted features depends on the point density and laser penetration of the canopy. Extracting appropriate features is a critical step to have accurate prediction models. Deep learning frameworks are increasingly being used in remote sensing applications. In the last objective of this study, a feature extraction approach is investigated for encoding LiDAR data acquired by UAV platforms multiple times during the growing season over sorghum and maize plant breeding experiments. LAI estimates obtained with these inputs are used to develop support vector regression (SVR) models using plant canopy analyzer data as the ground reference. Results are compared to models based on estimates from physically-based features and evaluated in terms of the coefficient determination (R2). The effects of experimental conditions, including flying height, sensor characteristics, and crop type, are also investigated relative to the estimates of LAI.