In real-time systems functional requirements are coupled to timing requirements, a specified event needs to occur at the appropriate time.  In order to ensure that timing requirements are fulfilled, there are two main approaches, static and measurement-based. The static approach relies on modeling the hardware and software and calculating upper bounds for the timing behavior. On the other hand, measurement-based approaches use timing data collected from the system to estimate the timing behavior. The usability of static and measurement-based approaches is limited in many modern systems due to the increased complexity of hardware and software architectures. Static approaches to timing and schedulability analysis are often infeasible due to their complexity. Measurement-based approaches require that design-time measurements are representative of the timing behavior at runtime, which is problematic to ensure in many cases. Designing systems that guarantee the timing requirements without excessive resource overprovisioning is a challenge. A Hidden Markov Model (HMM) describes a system where the behavior is state-dependent.  In this thesis, we model the execution time distribution of a periodic task as an HMM where the states are associated with continuous emission distributions. By modeling the execution times in this manner with a limited number of parameters, a step is taken on the path toward tracking and controlling timing properties at runtime.  We present a framework for parameter identification of an HMM with Gaussian emission distributions from timing traces, and validation of the identified models. In evaluated cases, the parameterized models are valid in relation to timing traces. For cases where design-time measurements are not representative of the system at runtime we present a method for the online adaptive update of the emission distributions of an HMM. Evaluation with synthetic data shows that the estimate tracks the ground truth distribution.  A method for estimating the deadline miss probability for a task with execution times modeled by an HMM with Gaussian emission distributions, in a Constant Bandwidth Server (CBS) is proposed. The method is evaluated with simulation and for a synthetic task with a known Markov Chain structure running on real hardware. / I realtidssystem är funktionella krav kopplade till tidskrav – en viss händelse måste inträffa vid rätt tid. För att försäkra sig om att tidskrav är uppfyllda finns två huvudsakliga metoder – statisk eller mätningsbaserad. En statisk analys baseras på modeller av hårdvara och mjukvara, och beräknar en övre gräns för tidsbeteendet. Mätningsbaserade analyser använder insamlat data från systemet för att uppskatta tidsbeteendet. Användbarheten av både statiska och mätningsbaserade metoder är begränsad i många moderna system eftersom komplexiteten hos hårdvara och mjukvara ökat. Statiska metoder är ofta omöjliga att genomföra på grund av komplexiteten. För mätningsbaserade metoder krävs att mätningarna som insamlats vid design är representativa för tidsbeteendet i drift, vilket är svårt att garantera i många fall. Att designa system som garanterar tidskraven utan överdriven resurstilldelning är en utmaning. En Hidden Markov Model (HMM) beskriver ett system med beteende som är tillståndsberoende. I denna avhandling modellerar vi exekveringstidens fördelning hos en periodisk task (uppgift) som en HMM där tillstånden är kopplade till kontinuerliga emissionsfördelningar. Genom att modellera exekveringstiderna på detta vis med ett begränsat antal parametrar, tar vi ett steg på vägen mot att följa och kontrollera tidsbeteendet i drift. Vi presenterar ett ramverk för parameteridentifiering för en HMM med Gaussiska emissionsfördelningar från tidsdata, och validering av de identifierade modellerna. De parametriserade modellerna är giltiga i relation till tidsdata i de fall som utvärderats. För fall när mätningar vid design inte är representativa för systemet i drift presenterar vi en metod för direkt adaptiv uppdatering av emissionsfördelningarna i en HMM. Utvärdering med syntetiska data visar att uppskattningen följer den sanna fördelningen. En metod föreslås för att uppskatta sannolikheten för att missa en deadline när exekveringstiden modelleras som en HMM med Gaussiska emissionsfördelningar hos en task i en Constant Bandwidth Server (CBS). Metoden utvärderas med simulering och med syntetiska program med känd Markov-struktur som körs på verklig hårdvara.

The increasing usage of electronics and software in a modern automobile enables realization of many advanced features. One such feature is autonomous driving. Autonomous driving means that a human driver’s intervention is not required to drive the automobile; rather, theautomobile is capable of driving itself. Achieving automobile autonomyrequires research in several areas, one of which is the area of automotive electrical/electronics (E/E) architectures. These architectures deal with the design of the computer hardware and software present inside various subsystems of the vehicle, with particular attention to their interaction and modularization. The aim of this thesis is to investigate how automotive E/E architectures should be designed so that 1) it ispossible to realize autonomous features and 2) a smooth transition canbe made from existing E/E architectures, which have no explicit support for autonomy, to future E/E architectures that are explicitly designed for autonomy.The thesis begins its investigation by considering the specific problem of creating autonomous behavior under cooperative driving condi-tions. Cooperative driving conditions are those where continuous wireless communication exists between a vehicle and its surroundings, which consist of the local road infrastructure as well as the other vehicles in the vicinity. In this work, we define an original reference architecture for cooperative driving. The reference architecture demonstrates how a subsystem with specific autonomy features can be plugged into an existing E/E architecture, in order to realize autonomous driving capabilities. Two salient features of the reference architecture are that it isminimally invasive and that it does not dictate specific implementation technologies. The reference architecture has been instantiated on two separate occasions and is the main contribution of this thesis. Another contribution of this thesis is a novel approach to the design of general, autonomous, embedded systems architectures. The approach introduces an artificial consciousness within the architecture, that understands the overall purpose of the system and also how the different existing subsystems should work together in order to meet that purpose.This approach can enable progressive autonomy in existing embedded systems architectures, over successive design iterations. / <p>QC 20130412</p>

Spin Torque Oscillator (STO) is a promising technology for microwave and radar applications due to its large tunability, miniature size, high operation frequency, high integration level, etc. However, the technology comes also with issues and challenges,such as low output power and spectrum impurity. For instance, in order to apply the STO technology into communication systems, an amplifier is required to compensate the STO’s low output power.     This thesis presents an amplifier for promising Magnetic Tunnel Junction (MTJ) STO devices. The motional resistance of different MTJ STO devices varies from several Ohms to hundreds Ohms, which makes the design challenging. This thesis focuses first on extracting the amplifier requirements using the state-of-the-art MTJ STO devices. The operation frequency of MTJ STO is in the range of 4-8GHzwith a -40～-60 dBm output power. Therefore, a wideband amplifier with 45-65 dB gain is required. Then based on the amplifier requirements, an amplifier topology is proposed, which is composed of two types of input balun-LNA stages depending onthe motional resistance of the STO, a broadband limiting amplifier and an outputbuffer. CG-CS architecture is suitable for the input balun-LNA in the small motional resistance case and cascoded-CS architecture is suitable for the large motional resistance case. The limiting amplifier and the output buffer are the common circuits shared by two cases via switches.     The wideband amplifier for STO is implemented using a 65nm CMOS process with 1.2 V supply and it exhibits 52.36 dB gain with 1.34-11.8 GHz bandwidth insmall motional resistance case and 59.29 dB gain with 1.171-8.178 GHz bandwidth in large motional resistance case. The simulation results show that the amplifier has very low power consumption and meets the linearity and noise performance requirements.

När tiden för utveckling av nya produkter kortas ner måste testning och verifiering utföras i ett tidigare utvecklingsstadie. Genom simulering av systemet kan tester utföras utan tillgång till det faktiska systemet och därmed kan utvecklingsprocessen accelereras. I BAE Systems Hägglunds stridsvagnar används en tröghetsnavigator som kan beräkna stridsvagnens position utan externa referenser. Test och verifiering av navigation med denna enhet i testbänk är ej fullt möjligt. Syftet med detta arbete är att kunna genomföra verklighetstrogna tester, i testbänk i utvecklingsfasen, genom att simulera navigatorns funktioner. Eftersom kommunikation med fordonssystemet ska ske i realtid samtidigt som navigationsdata läses från ett externt program, så ställs krav på att modellen har tillräcklig prestanda för att ge en verklighetstrogen simulering. Den övergripande frågeställningen i detta examensarbete är om en modell realiserad på en mikrokontroller (MCU) har tillräcklig prestanda för att användas vid simulering av en tröghetsnavigator. För att besvara frågeställningen har hårdvara för anpassning av gränssnittet mellan fordonssystem, MCU och externt program samt mjukvara för att simulera en tröghetsnavigator skapats. Därefter har modellen verifierats genom att mäta tiden för utvalda processer. Alla funktioner hos navigatorn har inte implementerats i simuleringsmodellen men resultaten visar att modellen kan användas för verklighetstrogna tester i testbänk. / When time for development of new products is shortened, testing and verification must be performed at an earlier stage of development. By simulating the system, tests can be performed without access to the actual system and thus the development process can be accelerated.  BAE Systems Hägglunds manufacture combat vehicles and use an Inertial Navigation System (INS) to calculate the combat vehicle’s position without external references. Testing and verification of navigation with this unit in the test bench is not entirely possible.  The aim of this thesis is to enable realistic tests, in a test bench in the development phase, by simulating the navigator’s functions. Since communication with the Vehicle Control System (VCS) must take place in real time at the same time as navigation data must be read from external program, the model is required to have sufficient performance to provide a realistic simulation.  The overall question in this thesis is whether a model realized on a microcontroller (MCU) has sufficient performance to be used for simulation of an INS. To answer the question at issue, hardware for adapting the interface between the VCS, MCU and external program as well as software for simulating an INS have been created. Thereafter, the model has been verified by measuring the time for selected processes.  Not all functions of the navigator have been implemented in the simulation model, but the results show that the model can be used for realistic tests in the test bench.

Energy-saving wireless sensors are increasingly used in the industry. Users can remotely monitor the status of the measured device and do not need to frequently replace the battery of the device. In this thesis, we studied a low-cost energy-independent wireless speed sensor system that can power itself by the rotation of the host. The BMG250 MEMS gyroscope is responsible for temperature and angular velocity measurement, and the nRF52832 SoC sends data to the remote monitoring terminal through BLE communication. This study aims to discover the energy consumption and energy saving methods of the entire process of data collection, data transfer, and data transmission. Finally, in order to meet the various test requirements, an energy consumption standard will be summed up to calculate the energy consumption of the entire system.

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Water is an important parameter for crop growth, and the information about the moisture content in soil at different depths is very useful for farmers to determine the best time to water the soil and to irrigate farmland so as to maximize their yield. This thesis project aims to develop a prototype of a multi-depth moisture sensor probe that is part of a large sensing system used in agriculture. The sensor probe has three sets and is required to last for 6-12 months of usage and to be reproduced at a low cost. The sensor probe consists of three sensor boards, on each of which has two different capacitive based sensors and one analog temperature sensor. The three boards are placed approximately 20 cm from each other in the probe. During this project, the two capacitive based sensors were developed, one with arc-shaped plates operating at a frequency less than 1 MHz, and one with electrodes in the form of annular rings operating at a high frequency, approximately 100 MHz. The moisture content in the soil is calculated based on the measurement of the frequency, which depends on the dielectric constant of the soil. For the implementation of the sensor probe, three printed circuit boards (PCBs) for the sensor boards were designed using Altium Designer and then ordered; an STM32 Nucleo board with low power microcontroller was used and the software was implemented in STM32CubeIDE. The lifetime of the sensor probe was calculated for different duty-cycles. With a duty-cycle of 15 minutes, where the sensor probe is active for 1 minute and in sleep mode for 14 minutes, the lifetime of the sensor probe would only be 16 days. With a duty-cycle of 120 minutes instead, with the sensor probe being active for 1 minute, the lifetime is increased to 130 days (less than4,5 months). Due to challenges with the high frequency capacitive sensor, the multi-depth sensor probe does not fully work, and thus cannot be tested with a large testbed. Further work needs to be conducted on the high frequency capacitive sensor and the communication with the gateway.

New and more capable electronics are required to push forward future space missions, and to pursue this goal the first step is the evaluation of novel technologies. The present thesis tackles the problem of evaluating new FPGA and memory technologies for spaceborne missions, while assessing its benefits and improvements. In this project, a novel soft SoC design based on the existing MDPA device was proposed and implemented. The new design includes a memory controller for the DDR3 technology, while targets a new radiation hardened FPGA technology. Additionally, the rad-hard FPGA is also assessed with the Cortex-R5 CPU to push its capabilities up to the limits. This latter, to find out how feasible is to use this FPGA to implement modern soft microprocessors. The thesis demonstrates that the new FPGA technology is able to match the current timing and resources requirements of the MDPA while improving its reliability. Also, it proves that the DDR3 technology has benefits over internal RAM in terms of bandwidth and capacity. Finally, it shows some problems when trying to use the FPGA technology to implement the Cortex-R5 CPU. / Ny och bättre elektronik behövs för att främja framtida rymduppdrag, och för att uppnå detta mål är ett första steg att utvärdera ny teknik. Denna avhandling behandlar problemet att utvärdera nya FPGAoch minnestekniker för uppdrag i rymden, och samtidigt avgöra vilka fördelar som finns med teknikerna och föreslå förbättringar. I detta projekt föreslogs och implementerades en ny mjuk SoCdesign baserad på den befintliga MDPA-enheten. Den nya designen inkluderar en minneskontroll för DDR3-tekniken, och är ämnad att byggas med hjälp av ny strålningshärdad FPGA-teknik. Dessutom testades den strålningshärdade FPGA-tekniken med Cortex-R5-CPU:n för att driva teknikens kapacitet till sin gräns. Detta för att avgöra om det är rimligt att använda denna FPGA för att implementera moderna mjuka mikroprocessorer. Avhandlingen visar att den nya FPGA-tekniken kan matcha de rådande tidsoch resurskraven på MDPA samtidigt som den förbättrar tillförlitligheten. Avhandlingen visar också att DDR3-tekniken har fördelar jämfört med intern RAM vad gäller bandbredd och kapacitet. Avhandlingen beskriver också några problem som uppstår när man försöker använda FPGA-tekniken för att implementera Cortex-R5-CPU:n.

Disc golf is one of the fastest growing sports in Sweden and the countrywide playerbase is steadily growing. In order to meet this increased demand, municipalities and sports associations alike have built new courses all around the country, which all require maintenence. Without an accurate way of determining course usage, it's difficult to guage how much money should be put towards maintaining and developing additional courses. The aim of this project was to design and test a people-counting system for disc golf couses which could provide this information to both players and course owners. Computer vision, wireless communication and sensor technologies were core topics explored during the development of the working prototype.

Autonomous vehicles rely on real-time embedded systems called Electronic Control Units (ECUs) and it is crucial for safety and behavioural correctness that ECUs run fast enough, in other words, within their deadlines. In this thesis a high-performance ECU used at Volvo Autonomous Solutions (V.A.S.) running PetaLinux will be evaluated. To ensure that the ECU is able to run in real-time, it will be evaluated by simulating physical models in the form of Functional Mock-up Units (FMUs) that are cross compiled to aarch64. The ECU execution time will be measured to evaluate whether the models run in real-time and to compare it with the performance of a desktop computer. With the use of profiling tools, possible bottlenecks in the utilization of ECU will be identified. The results show that the ECU is capable of running the FMU simulation models faster than real-time and that the ECU runs at less than 10% of the speed of the desktop computer. FMU communication frequency, underutilization of available instructions, unnecessary allocation and unnecessary use of synchronization primitives where identified as the key possible bottlenecks. We conclude that the ECU is likely capable of running significantly more computationally demanding models in real-time if they are optimized for the ECU.