The Generic Nanosatellite Bus (GNB) is a spacecraft platform designed to accommodate the integration of diverse payloads in a common housing of supporting components. The development of the GNB at the Space Flight Laboratory (SFL) under the Canadian Advanced Nanospace eXperiment (CanX) program provides accelerated access to space while reducing non-recurring engineering (NRE) costs. The work presented herein details the development of the attitude determination and control subsystem (ADCS) of the GNB. Specific work on magnetorquer coil assembly, integration, and testing (AIT) and reaction wheel testing is included. The embedded software development and unit-level testing of the GNB sun sensors are discussed. The characterization of the AeroAstro star tracker is also a major focus, with procedures and results presented here. Hardware models were developed and incorporated into SFL's in-house high-fidelity attitude dynamics and control simulation environment. This work focuses on specific contributions to the CanX-3, CanX-4&5, and AISSat-1 nanosatellite missions.

This thesis presents the formulation and validation of tracking algorithms for vehicular motion for use in active collision prevention in V2V communications. The main objective is to estimate position and velocity of a vehicle based on update from vehicular wireless network. By using vehicular wireless network, the range of position estimation improves when compare to conventional radars and sensors. On the other hand, from a vehicular wireless network point of view regular measurement information update is more difficult to obtain because of packet losses due to interference between communicating vehicles. Our proposed algorithms are based on methods from position tracking termed alpha-beta trackers in aerospace applications with constant rate of information updates, with some modifications to better solve the problem. We present the main algorithms and provide numerical evidence of their accuracy based on simulation data. The modified filters are shown to be computationally efficient (lightweight) and provide sufficient accuracy for estimation of vehicle positions based on information update in a wireless V2V system.

Radar target tracking problem has been a popular topic for several decades. Recent works have shown that the performance of tracking algorithms increases as more prior information is used by the system / such as maximum velocity and maximum acceleration of the target, altitude of the target, or the elevation structure of the terrain. In this thesis we will focus on increasing the performance of tracking algorithms making use of benefit from the elevation model of the environment where the target tracker is searching. For a constant target altitude and a certain radar location, we generate a &ldquo / visibility map&rdquo / using the elevation model of the terrain and use this information to estimate the location and the time that the target will reappear. The second aim of this work is to use the visibility map information for improving the performance of track initiation. For that purpose, a special map has been formed, that we call as the &ldquo / track initiation probability map&rdquo / , which shows the target first time appearance density. This information has been used at the initialization part of the track initiation algorithm in order to increase the performance.

L'axe conducteur de ce travail réside dans la maîtrise du positionnement relatif de deux solides. Pour positionner il faut mesurer. Dans ce travail, nous proposons une analyse conceptuelle des moyens de mesure existants. Certains permettent d'évaluer la position en suivant plusieurs coordonnées simultanément. Ainsi il est possible de "globaliser" l'acquisition. A partir de ce type de mesure, nous proposons des méthodes de dépouillement pour identifier les paramètres du modèle d'erreur, ainsi qu'un calcul de l'incertitude associée. Nous avons développé un principe de mesure permettant l'acquisition simultanée des 6 paramètres de position d'un solide, basé sur l'exploitation d'instruments de mesure de longueurs implantés suivant une architecture parallèle. La conception des instruments de mesure de longueurs a été déclinée sur plusieurs réalisations correspondant à des conditions de mise en oeuvre différentes. Nous sommes parvenus à obtenir une précision de ±3 μm sur une course de 600 mm.

Energy harvesting is becoming increasingly important in low-power applications where energy from the environment is used to power the system alone, or to supplement a battery. For example, pulse oximeter sensors inside helmets of road racing cyclists are powered by the sun. These sensors have become smaller and more practical without the limitation of a finite energy supply. Harvested energy from an energy transducer (solar, piezoelectric, etc.) must be maximized to ensure these devices can survive periods where environmental energy is scarce. The conversion process from the transducer to usable power for the device is not perfectly efficient. Specifically, the output voltage of a solar cell is a function of the light intensity, and by extension the load it powers. A small perturbation of the light source quickly diminishes the available power. The wasted power reduces the energy available for the application, and can be improved using an approach called maximum power point tracking (MPPT). This technique maximizes harvesting efficiency by dynamically impedance matching the transducer to its load. This report introduces the Maximum Efficient Solar Harvester (MESH), an MPPT algorithm tuned for a specific Wireless Sensor Network (WSN) application. MESH specifically controls the operation of the DC-DC converter in a solar power management unit (PMU). The control is done by monitoring the available light and feeding that information to choose the optimal operating point DC-DC converter. This operating point has a direct dependency on the overall efficiency of the system. For MESH to be practical, the cost and power overhead of adding this functionality must be assessed. Empirical results indicate that MESH improves the maximum efficiency of the popular Texas Instruments (TI) RF2500-SEH WSN platform by an average of 20%, which far exceeds the power overhead it incurs. The cost is also found to be minimal, as WSN platforms already include a large portion of the hardware required to implement MESH. The report was done in collaboration with Shahil Rais. It covers the hardware components and the bench automation environment; Rais's companion report focuses on software implementation and MESH architecture definition. / text

The pages of this dissertation detail the development of an advanced metrology instrument for measuring large optical surfaces. The system is designed to accurately guide the fabrication of the Giant Magellan Telescope and future telescopes through loose-abrasive grinding. The instrument couples a commercial laser tracker with an advanced calibration technique and a set of external references to mitigate a number of error sources. The system is also required to work as a verification test for the GMT principal optical interferometric test of the polished mirror segment to corroborate the measurements in several low-order aberrations. A set of system performance goals were developed to ensure that the system will achieve these purposes. The design, analysis, calibration results, and measurement performance of the Laser Tracker Plus system are presented in this dissertation.

This thesis presents the formulation and validation of tracking algorithms for vehicular motion for use in active collision prevention in V2V communications. The main objective is to estimate position and velocity of a vehicle based on update from vehicular wireless network. By using vehicular wireless network, the range of position estimation improves when compare to conventional radars and sensors. On the other hand, from a vehicular wireless network point of view regular measurement information update is more difficult to obtain because of packet losses due to interference between communicating vehicles. Our proposed algorithms are based on methods from position tracking termed alpha-beta trackers in aerospace applications with constant rate of information updates, with some modifications to better solve the problem. We present the main algorithms and provide numerical evidence of their accuracy based on simulation data. The modified filters are shown to be computationally efficient (lightweight) and provide sufficient accuracy for estimation of vehicle positions based on information update in a wireless V2V system.

The Iterative Closest Point (ICP) algorithm is one of the most commonly used range image processing methods. However, slow operational speeds and high input band-widths limit the use of ICP in high-speed real-time applications. This thesis presents and examines a novel hardware implementation of a high-speed ICP object tracking system that uses stereo vision disparities as input. Although software ICP trackers already exist, this innovative hardware tracker utilizes the efficiencies of custom hardware processing, thus enabling faster high-speed real-time tracking. A custom hardware design has been implemented in an FPGA to handle the inherent bottlenecks that result from the large input and processing band-widths of the range data. The hardware ICP design consists of four stages: Pre-filter, Transform, Nearest Neighbor, and Transform Recovery. This custom hardware has been implemented and tested on various objects, using both software simulation and hardware tests. Results indicate that the tracker is able to successfully track free-form objects at over 200 frames-per-second along arbitrary paths. Tracking errors are low, in spite of substantial noisy stereo input. The tracker is able to track stationary paths within 0.42mm and 1.42degs, linear paths within 1.57mm and 2.80degs, and rotational paths within 0.39degs axis error. With further degraded data by occlusion, the tracker is able to handle 60% occlusion before a slow decline in performance. The high-speed hardware implementation (that uses 16 parallel nearest neighbor circuits), is more then five times faster than the software K-D tree implementation. This tracker has been designed as the hardware component of ‘FastTrack’, a high frame rate, stereo vision tracking system, that will provide a known object’s pose in real-time at 200 frames per second. This hardware ICP tracker is compact, lightweight, has low power requirements, and is integratable with the stereo sensor and stereo extraction components of the FastTrack’ system on a single FPGA platform. High-speed object tracking is useful for many innovative applications, including advanced spaced-based robotics. Because of this project’s success, the ‘FastTrack’ system will be able to aid in performing in-orbit, automated, remote satellite recovery for maintenance. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-07-15 22:50:30.369

Στην παρούσα διπλωματική εργασία προσομοιώθηκε μέσω του προγράμματος Simulink ένα φωτοβολταϊκό σύστημα το οποίο αποτελούνταν από ένα φωτοβολταϊκό πλαίσιο των 60W, έναν DC/DC μετατροπέα Buck-Boost και ένα φορτίο. Στη συνέχεια εφαρμόσθηκαν τέσσερις διαφορετικές μέθοδοι ελέγχου στο φωτοβολταϊκό σύστημα με στόχο να λειτουργεί στο σημείο απόδοσης μέγιστης ισχύος (MPP) και συγκρίναμε τα αποτελέσματα της κάθε μια μεθόδου. Οι μέθοδοι που εφαρμόσθηκαν ήταν η μέθοδος Ανοιχτού Κυκλώματος (Open Voltage Method), η μέθοδος Διαταραχής και Παρατήρησης (Perturb and Observe Method), η μέθοδος Διαφορικής Αγωγιμότητας (Incremental Conductance) και προτείναμε και μια βελτιωμένη μέθοδο Διαταραχής και Παρατήρησης (Improved Perturb and Observe Method). / In this diploma thesis a photovoltaic system was simulated with the program Simulink. The photovoltaic system consisted of a photovoltaic panel of 60W, a buck-boost DC/DC converter and a load. Then four different control methods where applied so that the photovoltaic system would operate at the maximum power point (MPP) and the results of each control method were compared. The control methods which were applied were the Open Voltage Method, the Perturb and Observe Method, the Incremental Conductance Method and we proposed an improved Perturb and Observe Method.

Η εξέλιξη των συνεργατικών εφαρμογών χαρακτηρίζεται από συνεχή δημιουργία και βελτίωση μηχανισμών που προάγουν και διευκολύνουν τη συνεργασία. Η ενημερότητα και η εστίαση προσοχής αναμφισβήτητα παίζουν κύριο ρόλο σε μία επιτυχημένη συνεργασία, γιατί υποδεικνύουν άμεσα αν ο χρήστης έχει γνώση και αντίληψη της κατάστασης των συνεργατών του. Στην εφαρμογή Synergo που αναπτύσσεται από την Ερευνητική Ομάδα Επικοινωνίας Ανθρώπου-Υπολογιστή (Human-Computer Interaction Group - HCI Group)υ τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής σχολής του πανεπιστημίου Πατρών και υποστηρίζει τη συνεργασία χρηστών κατά τη δημιουργία διαγραμμάτων σε κοινή επιφάνεια εργασίας, προστέθηκαν μηχανισμοί που βελτιώνουν την ενημερότητα και την εστίαση προσοχής του χρήστη. Αναπτυσσονται οι έννοιες της συνεργασίας μέσω υπολογιστή, των φαινομένων προσοχής και της ενημερότητας επιφάνειας εργασίας. Αφού γίνεται μία θεωρητική προσέγγιση στις παραπάνω έννοιες, γίνεται επισκόπιση του εργαλείου eye-tracker, περιγραφή της εφαρμογής Synergo και εξηγείται ο τρόπος προσαρμογής των συγκεκριμένων μηχανισμών. Αναλύεται λεπτομερώς το πειραματικό στάδιο και τα αποτελέσματά του και γίνεται αξιολόγηση και προτάσεις για δυνατές μελλοντικές τροποποιήσεις της εφαρμογής / The evolution of collaborative software is characterized by continuous creation and improvement of the mechanisms that promote and help communication. Awareness and attention shifting indisputably play the first role in a successful collaboration because they show directly if the user has the knowledge and the perception of his partners' state. In Synergo, a software that is developed from the Human-Computer Interaction Group - (HCI Group) of Electrical Engineering and Computer Technology department of Patra's University and supports the collaboration between users during the creation of conceptual graphs in a common workspace, mechanisms that improve user's awareness attention were developed.The concepts of computer supported cooperative work, attention phenomena and workspace awareness are explained. After a theoretical approach of the above concepts, eye tracker and Synergo software are being described and the adding of the mechanisms is being explained.The experimental stadium and it's results are described with every detail and the software is evaluated. There are also proposals for possible future improvements.