A proposta deste trabalho é contribuir com a construção de uma plataforma de veículo autônomo para viabilizar as pesquisas na área pelo Departamento de Engenharia de Transportes da USP. Até o momento o departamento dispõe de uma plataforma que, a partir de sua posição conhecida, consegue navegar autonomamente até um ponto de destino utilizando apenas uma solução GNSS, no caso, GPS. Para ampliar a mobilidade da plataforma, está sendo sugerida aqui, a adição de sensores inerciais ao veículo, para que ele consiga obter uma solução de posição mesmo em áreas sem cobertura GNSS. Um Sistema de Navegação Inercial não depende de infraestrutura externa, exceto para inicializar suas variáveis, o que neste caso pode ser feito com auxílio de um receptor GPS. Sensores inerciais de alto desempenho são caros, tem alta complexidade mecânica e em geral são de grande porte. A alternativa é o uso de sensores do tipo MEMS que são pequenos, fáceis de serem manipulados e apresentam baixo consumo de energia. A contrapartida é que a solução é mais susceptível a ruído do que seus pares que custam na faixa de centena de milhões de dólares. / The proposal of this paper is to build an autonomous vehicle platform to enable the researches in this area by the Transport Engineering Department of the USP. Until now the Department has a platform that, once its initial position is known, it can navigate autonomously to a destination point using only the GNSS, in this case, GPS. To expand the mobility resources of the platform, it is being suggested here the addition of inertial sensors to the vehicle, enabling it to acquire a position solution even in areas where there is no coverage of the GNSS. An Inertial Navigation System does not depend on an external infra-structure, with the exception on the initial setup, where the GPS can be used to provide this kind of initialization. High performance inertial sensors are expensive, have high mechanical complexity and in general are big. The alternative is the usage of MEMS sensors, which are small, easy to handle and has low power consumption. In the opposite side this solution is more susceptible to noises in comparison to those High performance sensors that cost hundreds of thousands of dollars.

I detta examensarbete har en studie utförts för att ta fram och jämföra metoder att modellera krökta vangstycken av stål med komplexa geometrier i programmet Tekla Structures. Avgränsningen för studien har varit att jämföra två metoder: Metod 1 använder verktygen Complex Polybeam Creation i kombination med Surface Generation Between Polybeams i Tekla, och Metod 2 trappverktyget Spiral Staircase. En vindeltrappa från projektet Patienten och Princeton, Sankt Eriks ögonsjukhus i Hagastaden, har använts för att testa de komplexa geometrier som denna vindeltrappa medför. Utifrån detta har Tutorials av de båda metoderna skapats, för att läsaren enkelt ska kunna följa och genomföra samma steg. Resultatet av examensarbetet är att båda metoderna fungerar för modellering, beroende på vilken typ av geometri som skapas. Efter modellering med trappverktyget Spiral Staircase gick det inte att ta fram korrekta tillverkningsritningar av de horisontella plåtarna, till skillnad från Metod 1. Slutsatsen av studien är att vid enbart snabb modellering av cirkulära geometrier samt framtagning av tillverkningsritningar för vertikala krökta plåtar, kan med fördel Metod 2 användas. Däremot vid framtagning av tillverkningsritningar av komplexa och icke cirkulära geometrier lämpar sig Metod 1 bäst. / In this thesis, a study has been conducted to develop and compare methods of modeling curved stringer made of steel with complex geometries in the Tekla Structures program. The delimitation of the study has been to compare two methods: Method 1 uses the Complex Polybeam Creation tools in combination with Surface Generation Between Polybeams in Tekla, and Method 2 uses the tool Spiral Staircase. A spiral staircase from the project Patienten and Princeton, Sankt Eriks Eye Hospital in Hagastaden, Stockholm, has been used to test the complex geometries that this spiral staircase entails. Based on this, Tutorials of the two methods have been created, so that the reader can easily follow and implement the same steps. The result of this thesis is that both methods work for modeling, depending on the type of geometry that is created. After modeling with the tool Spiral Staircase, correct manufacturing drawings of the horizontal plates could not be obtained, unlike Method 1. The conclusion of the study is that with only rapid modeling of circular geometries as well as production of manufacturing drawings for vertical curved plates, Method 2 can be used with advantage. However, in the production of manufacturing drawings of complex and non-circular geometries, Method 1 is best suited.

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International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / With the rapid development of intelligent transport system in the world during the past few years, it promotes some navigation & location technology to a wide application especially in the car application. This paper firstly introduces some kinds of navigation & location systems and then analyzes the advantage and disadvantage of each system. On the basis of integrating every system and considering the high accuracy which can be achieved by adopting the technology based on DGPS (Differential Global Position System) at present, vehicle navigation & location system based on DGPS/INS/GIS integrated technology is put forward. The propound of this system shortens the distance between academic plan and real application greatly, and it provides a high accuracy and high reliability navigation & location system for traffic department and some car manufacturing Inc. In addition, this system is also provided with a friendly interface that makes it very easy to the manipulator or the user. The emphasis of this paper is put on the hardware and software of this system through introducing the system performance, the system component and the system software, and the characteristic of each module that makes up the whole system. The propound of the vehicle navigation & location system based on DGPS/INS/GIS integrated technology is a new attempt for development of intelligent transport system in our country, it will be sure to accelerate the process of our intelligent transport system.

Processing GPS carrier-phase measurements can provide high positioning accuracy for several navigation applications. However, if not detected, cycle slips in the measured phase can strongly deteriorate the positioning accuracy. Cycle slips frequently occur in areas surrounded by trees, buildings, and other obstacles. The dynamics experienced by the GPS receiver in kinematic mode of navigation also increases the possibility of cycle slips. Detection and correction of these cycle-slips is essential for reliable navigation. One way of detecting and correcting for cycle slips is to use another system to be integrated with GPS. Inertial Navigation Systems (INS), using three-axis accelerometers and three-axis gyroscopes, is integrated with GPS to provide more reliable navigation solution. Moreover, INS was utilized in the past for GPS cycle slip detection and correction. For low cost applications, Micro-Electro-Mechanical-Systems (MEMS) accelerometers and gyroscopes are used inside INS. For land navigation, reduced inertial sensor system (RISS) utilizing two accelerometers, one gyroscope, and the vehicle odometer was suggested. MEMS-based RISS has the advantage of using less number of MEMS-based gyroscopes and accelerometers thus reducing the overall cost and avoiding the complex error characteristics associated with MEMS sensors. In this thesis, we investigate the use of MEMS – based RISS to aid GPS and detect and correct for cycle slips. The Kalman filter was employed in centralized fashion to integrate the measurements from both GPS and RISS. This thesis research also offers a new threshold selection criterion resulting in a more robust cycle slip detection and correction. The proposed method was tested in different scenarios of road tests in land vehicle. Results show accuracy iii improvement over the conventional double differenced pseudoranges-based integrated system. Moreover, the adaptive selection criterion of the detection threshold proposed in this thesis improves the detection rate, especially in the case of small-sized cycle slips. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-05-06 18:11:57.076

This thesis is a description and analysis of work that I produced during my Gradate studies at the University of New Orleans. The central theme of these works is the common human experience of inner dialogue, an interior experience. Through prints and sculpture I produce stand-ins for the body. These objects are meant to invite the viewer to sense recognizable human traits and to experience the works as having been "lived in."

Creating 3D models of our surrounding world has seen a rapid increase in research and development over the last few years. A common method is to use laser scanners. Mapping is done either by ground based systems or airborne systems. With stationary ground-based laser scanning, or terrestrial laser scanning (TLS), it is possible to obtain high accuracy point clouds. But stationary TLS can often be a cumbersome and time-demanding task due to its lack of mobility. Because of this, much research has gone into mobilised TLS systems, referred commonly to as mobile laser scanning (MLS). Georeferencing point clouds to a world coordinate system is a difficult task in environments where global navigation satellite systems (GNSS) is unreliable. One such environment is forests, where the GNSS signal can be blocked, absorbed or reflected from the trees and canopy. Accurate georeference of points clouds for MLS systems in forests is difficult task that can be solved by using additional measurement instruments and post-processing algorithms to reduce the accumulation of errors, also known as drift. In this thesis a backpack-based MLS system to be used in forests was tested. The MLS system was composed of a GNSS, an inertial navigation unit (INS) and a laser scanner. The collected data was post-processed and analyzed to reduce the effects of detecting multiple ground layers and multiples of the same tree due to drift. The post-processing algorithm calculated tree and ground features to be used for adjusting the point cloud in the horizontal and vertical planes. The forest survey was done for an area roughly 40 meters in diameter. The MLS data was compared against TLS data as well as manual caliper data - where the caliper data was only measured in an area roughly 24 meters in diameter. The results indicated that the effects of multiple ground layers and multiple tree copies were removed after post-processing. Out of the total 214 TLS trees, 185 managed to be co-registered to MLS trees. The root mean square error (RMSE) and bias of the diameter at breast height (DBH) between the MLS andTLS data were 27.00 mm and -9.33 mm respectively. Co-registrationof the MLS and manual caliper data set gave 36 successful matches out of the total 43 manually measured DBH. The DBH RMSE and bias were 16.95 mm and -10.58 mm respectively. A Swedish TLS forest study obtained a DBH RMSE and bias (between TLS and caliper) of approximately 10 mm and +0.06 mm respectively. A Finnish backpack MLS forest study obtained a DBH RMSE and bias (between MLS and TLS) of 50.6 mm and +11.1 mm respectively. Evaluating the difference in radius at different heights along the tree stems between the MLS and TLS revealed a slight dependence on height, as the radius difference increased slightly closer to the stem base. The results indicated that backpack-based MLS systems has the potential for accurate lidar mapping in forests, and future development is of great interest to improve this system further.

The complementary advantages of GPS and INS have been the principle driving factor to integrate these two navigation systems as an integrated GPS/INS system in various architectural forms to provide robust positioning. Although the loosely coupled and tightly coupled GPS/INS systems have been in existence for over a decade or two and performed reasonably well, nevertheless, the tracking performance was still a concern in non-benign environments such as dynamic scenarios, indoor environments, urban areas, under foliages etc., where the GPS tracking loops lose lock due to the signals being weak, subjected to excessive dynamics or completely blocked. The motivation of this research, therefore, was to address these limitations with an integrated GPS/Pseudolite/INS system using ultra-tight integration architecture. The main research contributions are summarised as below: (a) The performance of the tracking loops in dynamic scenarios were analysed in detail with both conventional and ultra-tight software receivers. The stochastic modelling of the INS-derived Doppler is of utmost importantance in enhancing the benefits of ultra-tight integration, and therefore, two popular stochastic techniques??? Gauss Markov (GM) and Autoregressive (AR), were investigated to model the Doppler signal. The simulation results demonstrate that the AR method is capable of producing better accuracies and is more efficient. The algorithms to determine the AR parameters (order and coefficients) were also provided. (b) The various mathematical relationships that elicit the understanding of the ultra-tightly integrated system were derived in detail. The Kalman filter design and its implementation were also provided. Various simulation and real-time experiments were conducted to study the performance of the filter, and the results confirm the underlying assumptions in the theoretical analyses and the mathematical derivations. Covariance analysis was also performed to study the convergence and stability effects of the filter. (c) Interpolator design using signal processing techniques were proposed to increase the sampling rate of the INS-derived Doppler. To efficiently realise the interpolator transfer function, two optimal techniques were investigated ??? Polyphase and Cascaded Integrator Comb (CIC), and our results show that CIC was more efficient than polyphase in accuracy and real-time implementations. (d) The integration of Pseudolites (PL) with INS in ultra-tight configuration was analysed for an indoor environment. The acquisition and tracking performances of ???Pseudolites-only??? and ???Pseudolite/INS??? modes were compared to study the impact of the inertial signals aiding. The results demonstrate that aiding of the inertial signals with the baseband loops (acquisition and tracking) improve the overall tracking performance. An overview on the effects of the pseudolite signal propagation is also given. (e) Simulation and real-time experiments have been conducted to evaluate the proposed algorithms and the overall design of the ultra-tightly integrated system. A comparison was also done between GPS/PL/INS and GPS/INS integrated systems to study the potential advantages of the pseudolite integration. The details of the field experiment are provided. The data from a real-time experiment was processed to further evaluate the robustness of the system. The results confirm that the developed mathematical models and algorithms are correct.

The availability of GPS signals is a major limitation for many existing and potential applications. Fortunately, with the development of Galileo by the European Commission (EC) and European Space Agency (ESA) and new funding for the restoration of the Russian GLONASS announced by the Russian Federation the future for satellite based positioning and navigation applications is extremely promising. This research primarily investigates the benefits of GNSS interoperability and GNSS/INS integration to Receiver Autonomous Integrity Monitoring (RAIM) from a geometrical perspective. In addition to these investigations, issues regarding multiple outlier detection and identification are examined and integrity procedures addressing these issues are proposed. Moreover, it has been shown how the same RAIM algorithms can be effectively applied to the various static and kinematic navigation architectures used in this research.

Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system, consisting of a gyroscope and an odometer, along with a GPS via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to the standalone GPS. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this research is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system that is capable of computing the data-fused positioning solution instantly. The role of the developed system is to synchronize the measurements from the three sensors, GPS, gyroscope and odometer, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Xilinx’s MicroBlaze soft-core processor on a Virtex-4 FPGA is utilized and customized for developing the real-time navigation system. The soft-core processor offers the flexibility to choose or implement a set of features and peripherals that are tailored to the specific application to be developed. An embedded system design model is chosen to act as a framework for the work flow to be carried through the system life cycle starting from the system specification phase and ending with the system release. The developed navigation system is tested first on a mobile robot to reveal system bugs and integration problems, and then on a land vehicle testing platform for further testing. The real-time solution from the implemented system when compared to the solution of a high-end navigation system, proved to be successful in providing a comparable consistent real-time navigation solution. Employing a soft-core processor in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-10-11 16:08:38.811