In this thesis, effects of some software design patterns on real time software performance will be investigated. In real time systems, performance requirements are critical. Real time system developers usually use functional languages to meet the requirements. Using an object oriented language may be expected to reduce performance. However, if suitable software design patterns are applied carefully, the reduction in performance can be avoided. In this thesis, appropriate real time software performance metrics are selected and used to measure the performance of real time software systems.

Many real-time systems are developed and maintained through the use of commercial software products, such as Matlab and MatrixX, that automatically generate source code based on graphical control systems models. Testing these real-time models and the real-time software generated from them presents special problems during maintenance not faced with other forms of software. Very importantly, many of the models and software systems have to be tested through the use of simulations. Huge input and output data sets, the need for testing over a long duration of time (weeks or months), and computationally intensive requirements are just a few of the difficulties. For testing during maintenance in such situations, this paper draws upon field experience to present a set of test types and a strategy for selecting test types used to create series of input values to serve as test cases. Also this paper presents strategies for applying these test types, using the assistance of a free, widely available testing tool that automates test case generation, executes the simulations, and supports the analysis of the test results.

After the book, Design Patterns: Elements of Reusable Object-Oriented Software was published in 1994, usage of design patterns in object-oriented (OO) programming has been investigated by many researchers. However, the effects of design patterns on non-object oriented (non-OO) programming have not been analyzed too much in the literature. This study focuses on various design pattern implementations using non OO programming and investigates the benefits of design patterns upon real-time software. In order to evaluate the results, specific quality metrics were selected and performance of traditionally developed software was compared with that of software developed using design patterns.

[Truncated abstract] This thesis analyses the problem of Intelligent Control for large industrial plants and suggests a hierarchical, distributed, object-oriented architecture for Intelligent Control. The architecture is called MLIAC (Multi Level Intelligent Adaptive Control) Architecture. The MLIAC architecture is inspired by biological control systems (which are flexible, and are capable of adapting to unstructured environments with ease) and the success of the distributed architecture SCADA (Supervisory Control and Data Acquisition) Systems. The MLIAC Architecture structures the decision and control mechanism for the real-time properties namely safety, liveliness, and timeliness . . . In addition, three case studies have been reported. The case studies cover the control of a Flexible Manufacturing System and the Mine Products Quality Control. The results show that MLIAC Knowledge Representation model meets the requirements of the Roth-Hayes benchmark regarding Knowledge Representation. The decisions taken are logically tractable. The software architecture is effective and easily implemented. The actual performance has been found to depend upon a number of factors discussed in this thesis. For the specification and design of Potline MLIAC software, a CASE package ("Software Through Pictures") has been used. The Potline MLIAC software has been developed using C⁄C++, SQL, 4 GL and RDBMS based on a Client-Server model. For computer simulation the Potline MLIAC software has been integrated with the MATLAB⁄SIMULINK package.

Les interférences apparaissant dans les multicoeurs sont indésirables dans les systèmes tempsréel critiques, en particulier dans le domaine de l'aéronautique, où le déterminisme du fonctionnement temporel de tout système doit être formellement prouvé lors de la conception du système de manière à pouvoir être certifié et considéré comme opérationnel. Le but de cette thèse est de proposer une approche pour l'intégration logicielle d'applications IMA sur processeur multicoeur, sans impliquer de modification des plateformes logicielle et matérielle, et en respectant un maximum d'exigences de certification et concepts clés de l'avionique actuels, comme le partitionnement spatial et temporel ou encore la certification incrémentale. L'un des objectifs de la thèse est de respecter au maximum les procédés industriels d'intégration actuels de manière à maximiser les chances des contributions résultantes de la thèse d'être réutilisées au sein des industries avioniques. Un second objectif mineur est de permettre de réduire au minimum la phase d'adaptation des différents profils impliqués dans le processus d'intégration logicielle. Enfin, un troisième objectif est d'aider à optimiser le temps passé à effectuer les vérifications temporelles qui peuvent s'avérer difficiles et coûteuses en temps, mais aussi les choix architecturaux, de manière à réduire le time-to-market mais aussi optimiser le design du système en cours de conception. La contribution majeure de cette thèse est la proposition de deux stratégies complètes d'intégration logicielle/matérielle sur multicoeur pour des applications IMA. L'un des deux processus respecte les contraintes majeures de certification actuelles, ce qui en fait une stratégie potentiellement exploitable pour les applications les plus critiques de DAL A de l'aérospatial; la seconde offre un design le plus optimisé possible en termes de réduction de poids masse et consommation énergétique embarqués. Chaque stratégie est dite complète car elle contient: - une analyse temporelle statique qui borne les interférences inter-coeurs et permet de dériver des bornes supérieures de WCETs de manière fiable; - une formulation de problème de programmation par contraintes (PPC) pour l'allocation automatique et optimisée de logiciel sur matériel; la configuration résultante est correcte par construction car le problème de PPC exprimé exploite l'analyse temporelle mentionnée précédemment pour effectuer une vérification temporelle sur chaque configuration testée. - une formulation de problème de PPC pour la génération d'ordonnancement automatique et optimisé; la configuration résultante est correcte par construction car le processus exploite l'analyse temporelle mentionnée précédemment pour effectuer une vérification temporelle sur chaque configuration testée. / Interference in multicores is undesirable for hard real-time systems and especially in the aerospace industry, for which it is mandatory to ensure beforehand timing predictability and deadlines enforcement in a system runtime behavior, in order to be granted acceptance by certification authorities. The goal of this thesis is to propose an approach for multi-core integration of legacy IMA software, without any hardware nor software modification, and which complies as much as possible to current, incremental certification and IMA key concepts such as robust time and space partitioning. The motivations of this thesis are to stick as much as possible to the current IMA software integration process in order to maximize the chances of acceptation by avionics industries of the contributions of this thesis, but also because the current process has long been proven efficient on aerospace systems currently in usage. Another motivation is to minimize the extra effort needed to provide certification authorities with timing-related verification information required when seeking approval. As a secondary goal depending on the possibilities, the contributions should offer design optimization features, and help reduce the time-to-market by automating some steps of the design and verification process. This thesis proposes two complete methodologies for IMA integration on multi-core COTS. Each of them offers different advantages and has different drawbacks, and therefore each of them may correspond to its own, complementary situations. One fits all avionics and certification requirements of incremental verification and robust partitioning and therefore fits up to DAL A applications, while the other offers maximum Size, Weight and Power (SWaP) optimization and fits either up to DAL C applications, multipartition applications or non-IMA applications. The methodologies are said to be "complete" because this thesis provides all necessary metrics to go through all steps of the software integration process. More specifically, this includes, for each strategy: - a static timing analysis for safely upper-bounding inter-core interference, and deriving the corresponding WCET upper-bounds for each task. - a Constraint Programming (CP) formulation for automated software/hardware allocation; the resulting allocation is correct by construction since the CP process embraces the proposed timing analysis mentioned earlier. - a CP formulation for automated schedule generation; the resulting schedule is correct by construction since the CP process embraces the proposed timing analysis mentioned earlier.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Flight Safety concerns increase proportionally with increasing missile performance. These concerns are greatest in the near launch arena where a missile has the greatest potential energy. Systems such as radar, GPS tracking systems, and optics are normally of limited use in this arena for a number of reasons. A system was required that would provide useful tracking data in the first few seconds of a missile launch. This system has met that requirement providing nominal path deviation data from the launcher out to as much as 120 seconds. The tracking system described herein uses the principle of radio interferometry to derive phase difference measurements between carefully spaced antennas. These measurements are transmitted to the Operational Display Facility and converted to a usable angular deviation plot for use by Flight Safety Personnel. This paper provides an elementary radio interferometer system background and discusses this particular system setup and use. Some detail is provided on the premission simulation and setup of the system as well as the real-time display setup and output of the final data product.

Artificial neural network simulators are a research field which attracts the interest of researchers from various fields, from biology to computer science. The final objectives are the understanding of the mechanisms underlying the human brain, how to reproduce them in an artificial environment, and how drugs interact with them. Multiple neural models have been proposed, each with their peculiarities, from the very complex and biologically realistic Hodgkin-Huxley neuron model to the very simple 'leaky integrate-and-fire' neuron. However, despite numerous attempts to understand the learning behaviour of the synapses, few models have been proposed. Spike-Timing-Dependent Plasticity (STDP) is one of the most relevant and biologically plausible models, and some variants (such as the triplet-based STDP rule) have been proposed to accommodate all biological observations. The research presented in this thesis focuses on a novel learning rule, based on the spike-pair STDP algorithm, which provides a statistical approach with the advantage of being less computationally expensive than the standard STDP rule, and is therefore suitable for its implementation on stand-alone computational units. The environment in which this research work has been carried out is the SpiNNaker project, which aims to provide a massively parallel computational substrate for neural simulation. To support such research, two other topics have been addressed: the first is a way to inject spikes into the SpiNNaker system through a non-real-time channel such as the Ethernet link, synchronising with the timing of the SpiNNaker system. The second research topic is focused on a way to route spikes in the SpiNNaker system based on populations of neurons. The three topics are presented in sequence after a brief introduction to the SpiNNaker project. Future work could include structural plasticity (also known as synaptic rewiring); here, during the simulation of neural networks on the SpiNNaker system, axons, dendrites and synapses may be grown or pruned according to biological observations.

When developing three phase motor drives, the best way to validate the desiredfunctionality is to connect the inverter to an actual electrical motor. However, when developingfunctions which are not directly involved in controlling the motor, it could bemore efficient to use a real-time software model of the motor. In this master thesis, the developmentand implementation of a software model of a permanent magnet synchronousmotor (PMSM) is presented. This model was based on general dynamic equations forPMSM in a rotating reference frame (dq-frame). The model was simulated and convertedto C code using model based software development in Mathworks Simulink. To providemore realistic performance of the model, a finite element analysis (FEA) was done of anactual PMSM using the software tool FEMM. This analysis resulted in data describingthe relation between flux linkage and current which, when added into to software model,limits the produced torque due to magnetic saturation. Both the FEMM model and thefinal software model was compared to a corresponding actual motor for validation andperformance testing. All this resulted in a fully functional software model which was executableon the inverter. In the comparison of FEMM model to the real motor, a deviationin produced torque was discovered. This led to the conclusion that the model needed to beimproved to perform more alike the real motor. However, for this application the modelwas considered good enough to be used in future software development projects. / N¨ar kontrollsystem till trefasmotorer utvecklas s°a ¨ar det mest vanliga och troligendet b¨asta s¨attet f¨or funktionsvalidering att k¨ora drivenheten kopplad mot en riktig elektriskmotor. D¨aremot, om funktioner som ej ¨ar direkt kopplade till sj¨alva drivningen av motornutvecklas, s°a kan det vara mer effektivt att ist¨allet anv¨anda en mjukvarumodell. I det h¨arexamensarbetet s°a presenteras en mjukvarumodell av en permanentmagnetiserad synkronmotor(PMSM). Modellen baserades p°a de generella ekvationerna f¨or PMSM och simuleradessamt kodgenererades i Mathworks verktyg Simulink. F¨or att g¨ora modellen mer realistisks°a kompletterades den med data som beskriver relationen mellan det l¨ankade fl¨odetoch str¨om f¨or att ¨aven ta h¨ansyn till magnetisk m¨attnad. Den informationen simuleradesfram i verktyget FEMMgenom fl¨odesber¨akningar p°a en specifik motor typ. Samma motortyp har ocks°a j¨amf¨orts med den slutgiltiga mjukvarumodellen med avseende p°a utvecklatvridmoment vilket resulterade i n°agot st¨orre skillnader ¨an f¨orv¨antat. Slutsatsen blevs°aledes att modellen beh¨over f¨orb¨attras f¨or att p°a ett b¨attre s¨att st¨amma ¨overens med verklighetenmen att den fungerar tillr¨ackligt bra f¨or den ¨amnade applikationen.