In multi-sensor data fusion target tracking system, using information filtering can implement distributed location with uncorrelated measurement noises, but the measurement noises of different sensors are often correlated. If measurement noises are correlated, the covariance matrix of measurement noises is not a diagonal matrix. We can not use information filtering to implement distributed location with correlated measurement noises. By using the matrix theory, the covariance matrix of measurement noises can be transformed to a diagonal matrix. The observation models are transformed to new observation models, and the multi-sensor measurements with correlated measurement noises are transformed to equivalent pseudo ones with uncorrelated measurement noises. There are many methods in the matrix theory, we use Cholesky fatorization in this thesis. Cholesky fatorization is from Gaussian elimination, and there are many advantages in the computation process.However, the observation models need to be transformed to new observation models, and the measurement datas for the approach need to be separated and recombined. For measurement datas being separated and recombined, every sensor must communicate with each other. In practice, one sensor does not directly communicate with other sensors except its direct neighbors. By formulating the Cholesky factorization process, we present architectures which are applied in wireless distributed location. Distributed architectures with clustered nodes are proposed to achieve measurement exchange and information sharing for wireless location and target tracking. With limited times of data exchanges between clustered nodes, the correlated noise components in the measurements are transformed into uncorrelated ones through the Cholesky process, and the resultant information can be directly shared and processed by the derived extended information filters at the nodes in the distributed system. Hybrid TDOA/AOA wireless location systems with the NLOS error effects are used as examples in investigating the distributed information architecture. Simulation results show that the proposed distributed information processing and data fusion architecture effectively achieve improved location and tracking accuracy.

Thesis (Ph. D.)--Ohio State University, 2002. / Title from first page of PDF file. Document formatted into pages; contains xvi, 162 p. Includes abstract and vita. Advisor: Lawrence L. Feth, Dept. of Speech and Hearing Science. Includes bibliographical references (p. 141-148).

The introduction of input devices with natural user interfaces in gaming hardware has changed the way we interact with games. Hardware with motion-sensing and gesture recognizing capabilities remove the constraint of interacting with games through typical traditional devices like mouse-keyboard and gamepads. This changes the way we approach games and how the game communicates back to us as the player opening new levels of interactivity. This thesis covers how eye tracker technology can be used to affect rendering effects in games.

A white Gaussian noise measurement model is widely used in target tracking problem formulation. In practice, the measurement noise may not be white. This phenomenon is due to the scintillation of the target. In many radar systems, the measurement frequency is high enough so that the correlation cannot be ignored without degrading tracking performance. In this thesis, target tracking problem with correlated measurement noise is considered. The correlated measurement noise is modeled by a first-order Markov model. The effect of correlation is thought as interference, and Optimum Decoding Based Smoothing Algorithm is applied. For linear models, the estimation performances of Optimum Decoding Based Smoothing Algorithm are compared with the performances of Alpha-Beta Filter Algorithm. For nonlinear models, the estimation performances of Optimum Decoding Based Smoothing Algorithm are compared with the performances of Extended Kalman Filter by performing various simulations.

Στην παρούσα διατριβή διερευνήθηκε για πρώτη φορά η δυνατότητα επέκτασης του ορίου εφαρμογής της γεωδαιτικής μεθόδου μέτρησης μετακινήσεων σε πλέον άκαμπτες (υψίσυχνες) κατασκευές με τη χρήση οργάνων GPS δειγματοληψίας 100Hz. Τα όργανα αυτά αποτελούν πρόκληση για διάφορους τομείς καθώς έχουν δυνατότητα δειγματοληψίας σχεδόν ίδιας τάξης μεγέθους με όργανα που χρησιμοποιούνται παραδοσιακά για την καταγραφή δυναμικών κινήσεων όπως επιταχυνσιογράφοι, σεισμόμετρα κτλ. Στην παρούσα διατριβή μελετήθηκαν τα χαρακτηριστικά του θορύβου των οργάνων GPS-100Hz μέσα από συστηματικά πειράματα “supervised learning”, όπου στατικοί δέκτες ή δέκτες κινούμενοι σε γνωστές οριζόντιες και κατακόρυφες τροχιές, επέτρεπαν να καταγραφεί και να αναλυθεί ο στατικός και δυναμικός θόρυβος διαφόρων τύπων. Η περαιτέρω μελέτη του θορύβου έδειξε ότι οι συσχετίσεις και το εύρος του επηρεάζονται σημαντικά από το εύρος συχνοτήτων του βρόχου PLL (Phase-Locked Loop bandwidth) του δέκτη GPS. Η χρήση βρόχου PLL με εύρος συχνοτήτων (bandwidth) 100Hz εξασφαλίζει ασυσχέτιστες μετρήσεις αλλά αυξάνει σημαντικά το εύρος του θορύβου (τυπική απόκλιση περίπου 3mm στους οριζόντιους άξονες και περίπου 6-7mm στον κατακόρυφο). Το φάσμα συχνοτήτων του θορύβου των χρονοσειρών συντεταγμένων GPS-100Hz χαρακτηρίζεται από μη τυχαίο (χρωματισμένο) θόρυβο στις χαμηλές συχνότητες (μέχρι περίπου 0.5Hz) και πρακτικά τυχαίο θόρυβο για τις υψηλές συχνότητες. Επιπλέον λόγω της δυνατότητας υψηλού ρυθμού δειγματοληψίας των οργάνων GPS-100Hz, έγινε δυνατό να διερευνηθεί για πρώτη φορά το φαινόμενο της δυναμικής πολυανάκλασης του δορυφορικού σήματος από κινούμενες ανακλαστικές επιφάνειες (dynamic multipath) και η επίδρασή του στις χρονοσειρές στιγμιαίων συντεταγμένων GPS. Με βάση τα συμπεράσματα της ανάλυσης των πειραματικών δεδομένων αναπτύχθηκε μεθοδολογία απομείωσης του θορύβου των χρονοσειρών στιγμιαίων μετατοπίσεων κατασκευών ενδιαφέροντος Πολιτικού Μηχανικού με βάση ψηφιακά φίλτρα ζώνης. Η μεθοδολογία αυτή επιτρέπει να εκτιμηθούν οριζόντιες και κατακόρυφες μετακινήσεις της τάξης των λίγων χιλιοστών. Η παραπάνω μεθοδολογία εφαρμόστηκε στις καταγραφές των ταλαντώσεων μίας ξύλινης πεζογέφυρας στην περιοχή της Πάτρας. Από αφιλτράριστες μετρήσεις GPS-100Hz εκτιμήθηκε εύρος εγκάρσιας ταλάντωσης της τάξης των 60-70mm και συχνότητα ταλάντωσης 0.92Hz. Στον κατακόρυφο άξονα εκτιμήθηκε συχνότητα ταλάντωσης 6.5Hz ενώ μετά την απομάκρυνση του θορύβου των μετρήσεων εκτιμήθηκε εύρος κατακόρυφης ταλάντωσης της τάξης των 3mm. Η πειραματική και αναλυτική διερεύνηση δείχνουν ότι η υψηλή δειγματοληψία που παρέχουν τα νέα όργανα GPS-100Hz προσφέρει δυνατότητα καλύτερης εκτίμησης των χαρακτηριστικών ταλάντωσης (συχνότητα/εύρος) σχετικά εύκαμπτων κατασκευών αλλά και επέκτασης των ορίων εφαρμογής του GPS σε μέτρηση δυναμικών μετακινήσεων δύσκαμπτων κατασκευών (ιδιοσυχνότητα μεγαλύτερη των 5Hz) με εύρος μέχρι λίγα χιλιοστά. / The possibility of the newly introduced GNSS receivers, with sampling rate up to 100Hz, for broadening the limits of application of GPS technology toward measuring the displacements of stiff (high-frequency) Civil Engineering Structures was studied in the present thesis. The new generation GPS receivers present a great challenge for various applications since they offer a sampling rate similar to the sampling rate of traditional instruments used in vibration measurement/monitoring like accelerometers and seismometers. The noise characteristics of the 100Hz GPS measurements were studied on the basis of systematic “supervised learning” experiments where instantaneous coordinate time-series from stationary receivers or receivers performing motions with known characteristics permitted to study static and dynamic noise of several types including noise due to dynamic multipath. The last phenomenon has been identified during the measurements of the response of bridges due to excitation by passing vehicles. The study of noise characteristics indicated that the correlations and noise amplitude is highly dependent on the PLL (Phase-Locked Loop) bandwidth used by the GPS receiver. The use of a 100Hz PLL bandwidth ensures uncorrelated instantaneous coordinates but at the cost of high amplitude noise (standard deviation approximately 3mm and 6-7mm along the horizontal and vertical axes respectively). The noise spectrum is characterized by a power-law with colored noise affecting low frequencies up to approximately 0.5Hz and white noise affecting higher frequencies. A methodology for the reduction of noise of the instantaneous coordinate time-series using band-pass filtering has been designed on the basis of the results of the experimental data. Application of the methodology permits the identification of millimeter level dynamic displacements similar to the ones developed during structural vibrations. The methodology was applied on the measurements of the oscillations of a timber bridge in Patras, Greece. Oscillation amplitudes around 60-70mm and a fundamental natural frequency of 0.92Hz were identified along the lateral axis of the bridge on the basis of unfiltered GPS coordinates. The first natural frequency along the vertical axis was estimated at 6.5Hz. After the de-noising of the GPS coordinates vertical oscillation amplitudes of around 3mm were successfully identified. The main result from the experimental and analytical investigation carried out in the present thesis is that the newly introduced GPS receivers with sampling rate up to 100Hz provide the opportunity of more detailed measurement of the oscillations and extraction of the dynamic characteristics of relatively flexible structures as well as the broadening of the limits of applications of GPS toward the measurement of dynamic displacements of stiff (natural frequencies >5Hz) structures.

Surface quality plays a vital role in controlling the function performance of the workpiece. With the development of the measuring technique, areal surface measurement has been widely applied in the industry. However, estimating the uncertainty of areal surface measurement is still a challenge. Except for the metrological characteristics of the measurement system, measurement conditions should be considered for uncertainty evaluation. The dissertation investigates the influence of measurement settings on surface measurement. A silver-plated surface, three different rough grinding surfaces, and three different rough cylindrical grinding surfaces were measured using structured illumination microscopy. The measurements were at the different objective lenses, vertical scanning interval, exposure time, and sample tilt. The results show that the measurement settings influence the non-measured points, measurement noise, and areal surface texture parameters. Therefore, according to the investigation, the sample tilt and exposure time should also be included in the uncertainty budget. An approach was proposed to investigate the influence of non-measured points on the areal surface texture parameters. The relation between the non-measured points ratio and measurement settings was investigated, and how the areal surface texture parameters changed due to the non-measured points was studied. Moreover, an approach based on the metrological characteristic method was proposed to estimate the uncertainty due to the measurement noise. This method can be extended to the uncertainty evaluation due to other metrological characteristics. Additionally, an approach based on the Monte Carlo Method was proposed to estimate the measurement uncertainty due to different influences. This approach was verified as feasible in the practical measurement.

La surveillance des systèmes industriels et/ou embarqués constitue une préoccupation majeure en raison de l’accroissement de leur complexité et des exigences sur le respect des profilsde mission. La détection d’anomalies tient une place centrale dans ce contexte. Fondamentalement,les procédures de détection à base de modèles consistent à comparer le fonctionnement réel dusystème avec un fonctionnement de référence établi à l’aide d’un modèle sans défaut. Cependant,les systèmes à surveiller présentent souvent des dynamiques non linéaires et difficiles à caractériserde manière exacte. L’approche retenue dans cette thèse consiste à englober leur influencepar des incertitudes bornées. La propagation de ces incertitudes permet l’évaluation de seuils dedécision visant à assurer le meilleur compromis possible entre sensibilité aux défauts et robustesseaux perturbations tout en préservant une complexité algorithmique raisonnable. Pour cela, unepart importante du travail porte sur l’extension des classes de modèles dynamiques à incertitudesbornées pour lesquels des observateurs intervalles peuvent être obtenus avec les preuves d’inclusionet de stabilité associées. En s’appuyant sur des changements de coordonnées variant dans letemps, des dynamiques LTI, LPV et LTV sont considérées graduellement pour déboucher sur desclasses de dynamiques Non Linéaires à Incertitudes Bornées continues (NL-IB). Une transformationdes modèles NL-IB en modèles LPV-IB a été utilisée. Une première étude sur les non-linéaritésd’une dynamique de vol longitudinal est présentée. Un axe de travail complémentaire porte surune caractérisation explicite de la variabilité (comportement aléatoire) du bruit de mesure dansun contexte à erreurs bornées. En combinant cette approche à base de données avec celle à basede modèle utilisant un prédicteur intervalle, une méthode prometteuse permettant la détection dedéfauts relatifs à la position d’une surface de contrôle d’un avion est proposée. Une étude portenotamment sur la détection du blocage et de l’embarquement d’une gouverne de profondeur. / The monitoring of industrial and/or embedded systems is a major concern accordingto their increasing complexity and requirements to respect the mission profiles. Detection of anomaliesplays a key role in this context. Fundamentally, model-based detection procedures consist incomparing the true operation of the system with a reference established using a fault-free model.However, the monitored systems often feature nonlinear dynamics which are difficult to be exactlycharacterized. The approach considered in this thesis is to enclose their influence through boundeduncertainties. The propagation of these uncertainties allows the evaluation of thresholds aimingat ensuring a good trade-off between sensitivity to faults and robustness with respect to disturbanceswhile maintaining a reasonable computational complexity. To that purpose, an importantpart of the work adresses the extension of classes of dynamic models with bounded uncertaintiesso that interval observers can be obtained with the related inclusion and stability proofs. Based ona time-varying change of coordinates, LTI, LPV and LTV dynamics are gradually considered tofinally deal with some classes classes of nonlinear continuous dynamics with bounded uncertainties.A transformation of such nonlinear models into LPV models with bounded uncertainties has beenused. A first study on nonlinearities involved in longitudinal flight dynamics is presented. A complementarywork deals with an explicit characterization of measurement noise variability (randombehavior of noise within measurement) in a bounded error context. Combining this data-drivenapproach with a model-driven one using an interval predictor, a promising method for the detectionof faults related to the position of aircraft control surfaces is proposed. In this context, specialattention has been paid to the detection of runaway and jamming of an elevator.

One method to increase efficiency, robustness and accuracy of automatic control, is to introduce mathematical models of the system in question to increase performance. With these models, it is possible to predict the behavior of the system, which enables control according to the predictions. The problem here is that if these models do not describe the dynamics of the system well enough, this method could fail to increase performance. To address this problem, one idea is to estimate the dynamics of the system during operation, using methods for system identification, signal processing and sensor fusion. In this thesis, the possibilities of estimating a ship's dynamics during operation have been investigated. The mathematical model describing the dynamics of the ship is a graybox model, which is based on the physical and mechanical relations. This model's properties are therefore described by physical quantities such as mass and moment of inertia, all of which are unknown. This means that, when estimating the model, these physical properties will be estimated. For a systematic approach, first a simulation environment with a 4-degrees-of-freedom ship model has been developed. This environment has been used for validation of system identification methods. A model of a podded propulsion system has also been derived and validated. The methods for estimating the properties of the ship have been analyzed using the data collected from the simulations. For system identification and estimation of ship properties, the influence of measurement noise and potential of detecting a change in dynamics has been analyzed. This has been done through Monte Carlo simulations of the estimation method with different noise realizations in the simulations, to analyze how the measurement noise affects the variance and bias for the estimates. The results show that variance and bias vary a lot between the parameters and that even a small change in dynamics is visible in some parameter estimates when only ten minutes of data have been used. A method based on cumulative summation (CUSUM) has been proposed and validated to analyze if such a method could yield fast and effective detection of system deviations. The results show that the method is rather effective a with robust detection of changes in the dynamics after about four minutes of data collection. Finally, the methods have been validated on data collected on a real ship to analyze the potential of the methods under actual circumstances. The results show that the particular data is not appropriate for this kind of application along with some additional problems that can yield impaired results. / Genom att inkludera matematiska modeller som beskriver ett systems dynamik i styrningsalgoritmer, kan man åstadkomma en automatisk styrning med förbättrad effektivitet, robusthet och noggrannhet. Med dessa modeller går det att förutsäga beteendet hos systemet och därmed öppnas också möjligheten att använda sig av detta i styrningen. Problemet är att om dessa modeller inte beskriver systemets dynamik tillräckligt bra kan prestandan istället sänkas genom dessa metoder. Den här sortens problem kan man lösa genom att aktivt skatta systemets dynamik under körning, med hjälp av metoder för systemidentifiering, signalbehandling och sensorfusion. I denna exjobbsrapport har möjligheterna att skatta ett skepps girdynamik undersökts. Den matematiska modell som beskriver skeppets dynamik är en grålådemodell som baserar sig på fysikaliska och mekaniska samband. Denna modells egenskaper beskrivs därför av fysikaliska storheter så som massa, tröghetsmoment och tyngdpunkt, vilka alla är okända. Detta innebär att vid modellskattning skattas dessa fysikaliska storheter, vilka kan vara av stort intresse. En simuleringsmiljö med en skeppsmodell med fyra frihetsgrader har skapats och använts för att validera metoder för systemidentifiering. En modell av ett roterbart framdrivningssystem har också härletts och inkluderats i simuleringsmodellen. Vid systemidentifiering och skattning av skeppets egenskaper har dels inverkan av mätbrus analyserats samt även möjligheter till att detektera skillnader i dynamik. Detta har gjorts med Monte Carlo-simuleringar av skattningsmetoden med olika brusrealiseringar för att analysera hur mätbrus påverkar variansen och metodfelet hos skattningarna. Resultaten visar att vissa parametrar skattas med större noggrannhet och hos dessa kan därmed en förändring i dynamik identifieras när endast tio minuter av data har använts. En metod baserad på kumulativ summering av residualer har formulerats och validerats, detta för att undersöka om en sådan metod kan ge snabb och effektiv detektion av systemförändringar. Resultat visar på robusthet i att detektera skillnader i dynamik efter ungefär fyra minuter av datainsamling. Slutligen har metoderna validerats på data insamlad på ett riktigt skepp för att undersöka potentialen under verkliga omständigheter. Resultaten visar att just denna data inte är lämplig för denna applikation samt några problem som kan leda till försämrade resultat.

Les recherches sur les instationnarités des Interactions Ondes de Choc Couches Limites (IOCCL) turbulentes ont permis une description détaillée de celles-ci tant expérimentalement que numériquement . Ceci a conduit à plusieurs schémas susceptibles d'expliquer les respirations à basses fréquences observées dans de tels écoulements. Les configurations avec des conditions amont laminaires ou transitionnelles ont été moins étudiées.Dans le cadre du programme Européen TFAST, un important effort a été mené afin de développer des dispositifs expérimentaux, conjointement à des simulations numériques, permettant une étude détaillée de ces configurations. Dans le cadre de cette thèse, on a mis en place une configuration de réflexion d'onde de choc sur une couche limite laminaire pour un nombre de Mach de 1.68. L'utilisation des métrologies classiques (Anémométrie Laser Doppler, Anémométrie Fil Chaud), adaptées à ces conditions expérimentales particulières, a permis de décrire les propriétés spatio-temporelles de ces écoulements. Le champ moyen a été caractérisé et comparé aux théories classique et aux résultats obtenus dans différentes souffleries.Un schéma décrivant le mécanisme de transition à la turbulence au sein de l'interaction a été développé. Sa sensibilité aux conditions amont a été étudiée en plaçant des perturbations en amont de l'interaction. Dans tous les cas, des instationnarités convectives (haute fréquence) et stationnaires (basse fréquence) ont été observées et comparées à celles existantes pour les configurations amont turbulentes. Une gamme intermédiaire d'instationnarités convectives (moyenne fréquence) a été mise en évidence et caractérisée. / Research dedicated to the study of the unsteadiness of turbulent Shock Wave Boundary Layer Interaction (SWBLI) has allowed a detailed description of this kind of interaction both experimentally and numerically. Several scenario were proposed to explain the low frequency unsteadiness observed in separated SWBLI. Nevertheless, the literature on this kind of flow involving either upstream laminar or transitional conditions is quite reduce. Within the framework of the European TFAST program, an important effort was made to develop experimental devices, in conjunction with numerical simulations, allowing a detailed study of these laminar or transitional configurations. In particular, within the framework of this thesis, a shock wave reflection configuration on a laminar boundary layer was set-up, with a nominal free stream Mach number of 1.68. Using classical metrology (Laser Doppler Anemometry, Hot WireAnemometry) that have been adapted to these particular experimental conditions, we have been able to describe the spatio-temporal properties of the interaction. The mean field has been characterized and compared with the classical theories and the results obtained in other configurations.A model describing the transition mechanisms to turbulence within the interaction has been developed. Its sensitivity to upstream conditions was studied by placing perturbations upstream of the interaction. In all cases, convective (high frequency) and stationary (low frequency) unsteadiness were observed and compared with those existing for upstream turbulent configurations. An intermediate range of convective unsteadiness (medium frequency) has been demonstrated and characterized.