Le travail présenté dans ce manuscrit porte sur le développement d’un simulateur de cible (RTS) pour radars automobiles 77 GHz. Afin de proposer des véhicules toujours plus sûrs, les constructeurs automobiles développent des systèmes ADAS de plus en plus performants. On assiste aujourd’hui à la démocratisation des radars automobiles d’alerte à la collision et de régulation de distance. La généralisation de tels systèmes sur des véhicules de série va nécessiter le recours accru à des moyens de tests, chez les constructeurs et dans les centres de contrôle technique. Pour pouvoir tester et calibrer les radars, il est nécessaire d’utiliser des RTS. Ces appareils permettent de simuler les scénarios rencontrés par le radar, ceux-ci devenant plus complexes avec le développement des voitures autonomes. Une cible est définie par trois paramètres : une vitesse, une distance et une SER. Afin de répondre à des exigences drastiques, Autocruise développe ses propres RTS pour des bancs de test de production et de R&D. Ils doivent s’adapter à tout radar fonctionnant sur la bande 76 – 81 GHz, avec différentes modulations et une bande de fréquence supérieure à 800 MHz. Le système doit être à bas coût, de faibles dimensions et flexible pour être intégré dans différentes applications. Le principal verrou technologique est la réalisation d’une ligne à retard variable, capable de simuler des distances comprises entre 1 m et 250 m, avec une résolution de 0,2 m et permettre le contrôle de la SER. Un compromis devra être trouvé afin de répondre aux spécifications. L’étude a montré l’impossibilité de couvrir l’ensemble de la plage de distances avec une seule technologie. Une architecture hybride est indispensable. Une ligne à retard hybride reconfigurable large bande est présentée. / The work presented in this thesis concerns the development of an automotive radar target simulator for 77 GHz radar sensors. In order to continue offering safer vehicles, manufacturers develop more and more performant ADAS systems. We are witnessing a democratization of automotive radar sensors for adaptive cruise control and collision warning. The generalization of such systems on standard cars will require an increased use of test devices both at the manufacturers and in technical control centers. To test and calibrate radars, it is necessary to use Radar Target Simulators (RTS). These devices enable to simulate situations encountered by the radar. Furthermore, these scenarios are becoming increasingly complex with the arrival of autonomous vehicles. A target is defined by three parameters: distance, velocity and radar cross-section (RCS). In order to meet drastic requirements, ZF TRW Autocruise develops its own RTS for production test benches and R&D. RTS must adapt to all radars within a 76 – 81 GHz frequency band, with different modulations and a frequency bandwidth higher than 800 MHz. The system must present the advantages of being a low-cost system, with small dimensions and flexible to be integrated in different applications. The major blocking point is the design of a reconfigurable delay line, able to simulate distances between 1 m and 250 m with a resolution of 0.2 m on a large frequency band and also allowing control of RCS. A compromise will have to be found in order to meet the different specifications. The study showed the impossibility to cover the entire range of distances with one single technology. A hybrid architecture is necessary. A hybrid, tunable, wideband delay line is at study.

Entre los parámetros de cálculo más importantes en la Mecánica de Rocas, se encuentra la Resistencia a Comprensión Simple, como un valor que nos ayuda a la caracterización y estudio del comportamiento de los macizos rocosos. Contar con una buena correlación entre el ensayo de Carga Puntual (PLT) y de Resistencia a Compresión Simple (RCS) puede ser de gran importancia, pues se obtienen beneficios por la realización de ensayos más rápidos y económicos, que pueden aportar la misma seguridad en los cálculos de estructuras y actuaciones en macizos rocosos. Un paso previo para poder aplicar dicha correlación es disponer de un buen método de determinación de la Resistencia a la Carga Puntual. Esa correcta determinación es bastante confiable cuando se dispone de un número suficiente de ensayos con probetas de la misma naturaleza, pero habitualmente no es así y debe aplicarse un factor de corrección por tamaño F=(De / 50)? , con un ? = 0,45. En el presente trabajo se estudia la adecuación de dicho factor y se inicia el estudio de un factor alternativo, para el que se propone una expresión en la que el exponente ? es del tipo ?* = C1 - C2 x Is(50),F, donde Is(50),F es el índice de resistencia a la Carga Puntual obtenido con el factor F normativo. También, es importante conocer antes de realizar los ensayos de PLT, las dimensiones óptimas de las probetas (relación L / D) para una adecuada aplicación de la carga (P). El trabajo se centra en las Calizas de la Comunidad Valenciana (España) porque representan un porcentaje muy elevado de las rocas existentes en esa comunidad. Para su ejecución se han realizado más de 700 ensayos in-situ y en laboratorio, de los cuales 346 son ensayos de PLT, 45 ensayos de RCS y el resto son determinaciones de otros parámetros caracterizadores como son: peso específico y porosidad, durabilidad al desmoronamiento (Slake-Durability), velocidad ultrasónica, etc. / Galván Ceballos, MA. (2011). Estudio del ensayo a carga puntual en materiales calizos de la Comunidad Valenciana. Propuesta de modificación del factor de corrección por tamaño y correlación del ls(50) con la Resistencia a Compresión Simple [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10526 / Palancia

No description available.

The goal of this 15 hp thesis in computer engineering was to develop a tool for monitoring and analyzing the data flow on a Controller Area Network (CAN) called Rig Control System (RCS) that is used by Atlas Copco. Atlas Copco develops and manufactures machines for Mining and Rock Excavation. The Rocktec division is responsible for the Rig Control System platform used on machines in all division within the Mining and Rock Excavation Technique (MR) business area. The tool’s primary purpose is monitor and analyze data from the RCS network and present the analyzed data in an easy way to help with development and maintenance of RCS and machines that use RCS. The advantages and how data is sent over the CAN bus are presented as well as the CANopen protocol which is a higher layer protocol based on CAN. Two ways of data acquisition from RCS are presented, a simulated environment and real hardware. Different types of interprocess communication are presented as well as the pros and cons of each of these types. The creation of the tool required a Graphical User Interface (GUI) so different frameworks for this task are also presented and discussed. A version of the tool is presented and discussed in detail. The result of the project is a tool that with further development can be of great use to developers and service engineers working with RCS. / Målet med detta 15 hp examensarbete inom datateknik var att utveckla ett verktyg för att övervaka och analysera dataflödet på ett Controller Area Network (CAN) kallat Rig Control System (RCS) som används av Atlas Copco. Atlas Copco utvecklar och tillverkar maskiner för gruvdrift och bergbrytning. Rocktec-divisionen är ansvarig för Rig Control System-plattformen som används i maskiner från alla avdelningar inom affärsområdet Mining and Rock Excavation Technique (MR). Verktygets primära uppgift är att övervaka och analysera data från RCS-nätverket och presentera den analyserade datan på ett lättöverskådligt sätt för att vara till hjälp vid utveckling och underhåll av RCS och maskiner som använder RCS. Fördelar, hur data skickas över CAN-bussen och även CANopen-protokollet, som är ett högnivåprotokoll baserat på CAN, presenteras. Två olika sätt att samla in data från RCS presenteras, en simulerad miljö och riktig hårdvara. Olika typer av interprocesskommunikation och deras respektive fördelar och nackdelar presenteras. Skapandet av verktyget krävde ett grafiskt användargränssnitt så olika ramverk för denna uppgift presenteras och diskuteras i detalj. Resultatet av projektet är ett verktyg som med vidare utveckling kan vara till stor användning för utvecklare och servicetekniker som arbetar med RCS.

Autonomous cars are developing in a rapid speed, which means that the advanced driver-assistance systems must be tested carefully. Radar is one of many tools the car can use to detect obstacles and targets in front of the car. This bachelor thesis deals with programming and testing of an FMCW radar. The radar used in this thesis is an Continental ARS 308-2C/21 HS/AO, and the programming is written in Visual Basic. The goal within this project was to write a program for the Continental radar, and then measure static objects. The radar and the written program will be used in the research project, "HiFi Radar Target". The radar module will also be implemented in the new EMC chamber, AWITAR, which is currently under construction. The radar sweeps in the frequency band 77GHz, which is a standard frequency in the automotive industry. Communication with the computer is done via a CAN-network. Function tests have been performed on Astazero and gave satisfactory results.The thesis work has been carried out at RISE in Borås. / Idag är självkörande bilar på kraftig frammarsch, detta medför att hjälpsystemen måste testas noga. Radar är ett av många hjälpmedel bilen kan använda för att detektera hinder framför bilen. Detta examensarbete avhandlar programering och testning av en FMCW radar. Radarn som används är en Continental ARS 308-2C/21 HS/AO, programeringen är skriven i Visual Basic. Målet med detta examensarbeta var att få radarn att fungera, för att sedan kunna mäta på statinära objekt. Radarn och det skrivna programmet kommer att användas inom forskningsprojektet, "HiFi Radar Target". Radarmodulen kommer även att implementeras i den nya EMC-kammaren, AWITAR som just nu är under konstruktion. Radarn sweper i freqvensbandet 77GHz, vilket är en standardfreqvens för bilindustrin. All kommunikation med radarn och datorn sker via ett CAN-nätverk. Funktionstesterna har utförts på Astazero och gav tillfredställande resultat. Examensarbetet är utfört på RISE i Borås.

In this study, a computer code is developed in MATLAB&reg / to compute the Radar Cross Section (RCS) of arbitrary shaped complex targets by using Physical Optics (PO) and Modified PO. To increase the computational efficiency of the code, a novel fast integration procedure for oscillatory integrals, called Levin&rsquo / s integration, is applied to PO integrals. In order to improve the performance of PO near grazing angles and to model diffraction effects, a method called PO with Modified Surface Normal Vectors is implemented. In this method, new surface normals are defined to model the diffraction mechanism. Secondary scattering mechanisms like multiple scattering and shadowing algorithms are also included into the code to obtain a complete RCS prediction tool. For this purpose, an iterative version of PO is used to account for multiple scattering effects. Indeed, accounting for multiple scattering effects automatically solves the shadowing problem with a minor modification. Therefore, a special code for shadowing problem is not developed. In addition to frequency domain solutions of scattering problems, a waveform analysis of scattered fields in time domain is also comprised into this thesis. Instead of direct time domain methods like Time Domain Physical Optics, a Fourier domain approach is preferred to obtain the time domain expressions of the scattered fields. Frequency and time domain solutions are obtained for some simple shapes and for a complex tank model for differently polarized incident fields. Furthermore, a statistical analysis for the scattered field from the tank model is conducted.

Les travaux de cette thèse s'inscrivent dans le contexte des réseaux sans fil et des réseaux d'accès par Satellite en particulier, qui facilitent l'installation d'infrastructures réseau dans les zones géographiquement reculées et faiblement peuplées. Cependant, ces derniers présentent certains inconvénients lorsqu'il s'agit de déployer des applications multimédia interactives. En effet, de telles applications requièrent un délai de bout en bout aussi faible que possible et plus généralement exigent une meilleure Qualité de Service (QdS) du système de communication que le classique Meilleur-Effort (BE) afin de fonctionner correctement. Or, les réseaux d'accès par satellite géostationnaires souffrent déjà d'un délai de propagation non négligeable d'autant plus accru que la transmission des données est assurée par des mécanismes d'allocation dynamique, par exemple dans un système DVB-S2/RCS. Dans ces travaux de thèse, nous proposons d'utiliser les informations de signalisation de session des applications multimédia basées sur le protocole de session SIP afin d'ajuster le paramétrage du système de communication selon une approche " cross-layer " qui permet alors d'améliorer de façon significative la réactivité du système. Nous avons proposé plusieurs solutions pour, d'abord réduire le temps entre la demande de communication et le démarrage effectif du transfert des flux multimédia, ensuite réduire le délai de transmission des données multimédia durant la communication (tout en utilisant de manière optimale les ressources réseau disponibles sur la voie retour), et enfin accroître le nombre de flux multimédia admissibles dans le réseau satellite tout en leur garantissant un niveau de QdS satisfaisant. Afin de faciliter l'intégration et l'implémentation des solutions proposées dans un système de communication réel, un mécanisme de communication inter-couches d'optimisation est proposé et développé. De plus, une architecture orientée web services est utilisée afin de faciliter la découverte et l'invocation des différentes niveaux de services de communication présents dans de tels réseaux d'accès. Les solutions proposées ont été évaluées dans des environnements sans fil émulés et réels

In this thesis the cubic spline guidance law and its variants are derived. A detailed analysis is carried out to find the initial conditions for successful interception. The results are applied to three dimensional guidance design and for solving waypoint following problems. The basic cubic spline guidance law is derived for intercepting a stationary target at a desired impact angle in a surface-to-surface engagement scenario. The guidance law is obtained using an inverse method, from a cubic spline curve based trajectory. For overcoming the drawbacks of the basic cubic spline guidance law, it is modified by introducing an additional parameter. This modification has an interesting feature that the guidance command can be obtained using a single cubic spline polynomial even for impact angles greater than π/2, while resulting in substantial improvement in the guidance performance in terms of lateral acceleration demand and length of the trajectory. For imparting robustness to the cubic spline guidance law, in the presence of uncertainties and acceleration saturation, an explicit guidance expression is also derived. A comprehensive capturability study of the proposed guidance law is carried out. The capturability for the cubic spline guidance law is defined in terms of the set of all feasible initial conditions for successful interception. This set is analytically derived and its dependence on various factors, such as initial engagement geometry and interceptor capability, are also established. The basic cubic spline guidance and its variants are also derived for a three dimen- sional scenario. The novelty of the present work lies in the particular representation of the three dimensional cubic spline curve and the adoption of the analytical results available for two dimensional cubic spline guidance law. This enables selection of the boundary condition at launch for given terminal boundary condition and also in avoiding the singularities associated with the inverse method based guidance laws. For establishing the feasibility of the guidance laws in the real world, the rigid body dynamics of the interceptor is presented as a 6 degrees-of-freedom model. Further, using a simplified model, elementary autopilots are also designed. The successful interception of the target in the presence of the rigid body dynamics proves practical applicability of the cubic spline based guidance laws. Finally, the theory developed in the first part of the thesis is applied to solve the waypoint following problem. A smooth path is designed for transition of vehicle velocity from incoming to outgoing direction. The approach developed is similar to Dubins’ path, as it comprises line–cubic spline–line segments. The important feature of this method is that the cubic spline segments are fitted such that the path curvature is bounded by a pre-specified constrained value and the acceleration demand for following the smooth path obtained by this method, gradually increases to the maximum value and then decreases. This property is advantageous from a practical point of view. All the results obtained are verified with the help of numerical simulations which are included in the thesis. The proposed cubic spline guidance law is conceptually simple, does not use linearised kinematic equations, is independent of time-to-go es- timates, and is also computationally inexpensive.

Cette thèse élargie le champ des applications de l’analogie microonde en adaptant les techniques de fabrication permettant de contrôler les analogues et en développant un outil versatile et précis pour réaliser les mesures. L’analogie microonde consiste à transposer à l’échelle microonde les objets dont nous souhaitons étudier la diffraction en créant un analogue respectant le même rapport dimension sur longueur d’onde, et les mêmes propriétés morphologiques électromagnétiques. Une attention particulière a été portée aux objets faiblement diffractant ayant des niveaux SER aussi faibles que -60 dBm2. A la suite de la caractérisation des réflexions parasites et de celle du bruit aléatoire perturbant les mesures, une nouvelle technique d’optimisation du paramétrage des appareils de mesure a été proposée. Elle comporte notamment un réglage des puissances de source en fonction des angles de bistatisme et un filtrage temporel, par switch, qui a été mis en place et paramétré pour filtrer les signaux parasites mesurés. Les bénéfices de ces diverses optimisations des paramètres de mesures ont été démontrés et ils ont permis de mesurer précisément des niveaux de SER très faibles. De plus, la mise en œuvre de la fabrication additive a permis de réaliser des analogues de géométrie maîtrisée avec des permittivités relatives locales à la carte ayant des parties réelles dans la gamme de 1 à 3 ; la permittivité étant ajustée par contrôle de la porosité. Les trois principales études présentées concernent : des sphéroïdes de faible permittivité, analogues de micro-algues, des agrégats de suies de forme complexes, et des scènes forestières composées d’analogues d’arbres et de véhicules. / This thesis widens the application of the microwave analogy by adopting the appropriate techniques to create objects of controlled shapes and electromagnetic properties using novel manufacturing technologies, as well as by developing a versatile setup providing accurate measurements. Microwave analogy is a useful approach to investigate a scattering problem when the targets have nanometric or metric sizes. The experiment is scaled to the microwave range and the target is mimicked by a centimeter-sized analog, while maintaining the same initial wavelength over target’s dimension ratio and conserving the same geometric and electromagnetic properties. A special attention is given to low scattering targets with RCS levels down to -60 dBm2. The random noise of the measurement setup was characterized and a novel optimization technique was proposed which consists of an angular decomposition of the bistatic region with different power profiles. The undesired reflections within the anechoic chamber were identified and a Hardgating system was installed, allowing to filter out the stray signals. In addition, additive manufacturing technologies were involved in the fabrication of analogs and a novel technique was proposed to obtain targets with “on-demand” shapes and local values of their complex permittivity. We can manufacture low scattering analogs of the real part of permittivity for any value between 1 and 3 by creating well controlled porous structures. The three main targets are studied: low permittivity spheroids, analogs of microalgae, soot aggregates analogs with complex shape, and scaled forest scene composed of tree analogs with some metal vehicle analogs.

Estimation of the Radar Cross Section of large inhomogeneous scattering objects such as composite aircrafts, ships and biological bodies at high frequencies has posed large computational challenge. The detection of scattering from wake vortex leading to detection and possible identification of low observable aircrafts also demand the development of computationally efficient and rigorous numerical techniques. Amongst the various methods deployed in Computational Electromagnetics, the Method of Moments predicts the electromagnetic characteristics accurately. Method of Moments is a rigorous method, combined with an array of modeling techniques such as triangular patch, cubical cell and tetrahedral modeling. Method of Moments has become an accurate technique for solving electromagnetic problems from complex shaped homogeneous and inhomogeneous objects. One of the drawbacks of Method of Moments is the fact that it results into a dense matrix, the inversion of which is a computationally complex both in terms of physical memory and compute power. This has been the prime reason for the Method of Moments hitherto remaining as a low frequency method. With recent advances in supercomputing, it is possible to extend the range of Method of Moments for Radar Cross Section computation of aircraft like structures and radiation characteristic of antennas mounted on complex shaped bodies at realistic frequencies of practical interest. This thesis is a contribution in this direction. The main focus of this thesis is development of parallel Method of Moments solvers, applied to solve real world electromagnetic wave scattering and radiation problems from inhomogeneous objects. While the methods developed in this thesis are applicable to a variety of problems in Computational Electromagnetics as shown by illustrative examples, in specific, it has been applied to compute the Radar Cross Section enhancement due to acoustic disturbances and flow inhomogeneities from the wake vortex of an aircraft, thus exploring the possibility of detecting stealth aircraft. Illustrative examples also include the analysis of antenna mounted on an aircraft. In this thesis, first the RWG basis functions have been used in Method of Moments procedure, for solving scattering problems from complex conducting structures such as aircraft and antenna(s) mounted on airborne vehicles, of electrically large size of about 45 and 0.76 million unknowns. Next, the solver using SWG basis functions with tetrahedral and pulse basis functions with cubical modeling have been developed to solve scattering from 3D inhomogeneous bodies. The developed codes are validated by computing the Radar Cross Section of spherical homogeneous and inhomogeneous layered scatterers, lossy dielectric cylinder with region wise inhomogeneity and high contrast dielectric objects. Aerodynamic flow solver ANSYS FLUENT, based on Finite Volume Method is used to solve inviscid compressible flow problem around the aircraft. The gradients of pressure/density are converted to dielectric constant variation in the wake region by using empirical relation and interpolation techniques. Then the Radar Cross Section is computed from the flow inhomogeneities in the vicinity of a model aircraft and beyond (wake zone) using the developed parallel Volume Surface Integral Equation using Method of Moments and investigated more rigorously. Radar Cross Section enhancement is demonstrated in the presence of the flow inhomogeneities and detectability is discussed. The Bragg scattering that occurs when electromagnetic and acoustic waves interact is also discussed and the results are interpreted in this light. The possibility of using the scattering from wake vortex to detect low visible aircraft is discussed. This thesis also explores the possibility of observing the Bragg scattering phenomenon from the acoustic disturbances, caused by the wake vortex. The latter sets the direction for use of radars for target identification and beyond target detection. The codes are parallelized using the ScaLAPACK and BiCG iterative method on shared and distributed memory machines, and tested on variety of High Performance Computing platforms such as Blue Gene/L (22.4TF), Tyrone cluster, CSIR-4PI HP Proliant 3000 BL460c (360TF) and CRAY XC40 machines. The parallelization speedup and efficiency of all the codes has also been shown.