This master’s thesis deals with the design of autonomous monitoring system electronics which will be used for diagnostics of the electromagnetic vibration generator developed at Brno University of Technology. This generator should be used in a practical application where frequent mechanical shocks are present, for example in vehicle or goods transportation. For such an application, the goal of the monitoring system is to find out whether generator is capable of producing enough electrical energy for smooth operation of wireless sensors used in similar applications. The first part of the thesis consists of the autonomous diagnostics system overview from both commercial and scientific spheres, brief description of the vibration generator used and also a summary of commercially available power management electronics. The next chapters present the detailed description of each functional element of energy harvesting system, the simulation of generator’s behaviour for optimal load in three different model applications and the most important part – design of the autonomous monitoring system. In the end, achieved results are evaluated and it is considered whether the shock-driven generator is suitable for use in a given application.

Dissertation thesis is focused on using alternative energy sources called energy harvesting. This thesis offers a solution to problems with autonomous powering of sensor networks if primary power source recovery is impossible. In these cases, energy of the external power (e.g. temperature, light, motion) should be used. Proposed solution should be especially used in the field of medical applications (e.g. cochlear implants, pacemakers, insulin pumps). Long time monitoring of the personal health status is also possible when employing automated sensor systems. In this work, there is state of art review relating to the low power energy sources for an alternative powering of sensor systems. It was observed that existing systems are almost prepared for the implementation of energy harvesting power sources. The energy harvesting power sources have been developed by numerous researcher teams around the world, but there are only a few variants of power management circuits for effective energy gaining, storing and using. This area has a huge potential for the next research. The issues regarding to the distribution of gained energy are solved on the complex level in the thesis. For these purposes, a new simulation model of the whole system (fully implantable artificial cochlea) including its subcircuits was developed in the SPICE environment. It connects independent subcircuits into a single comprehensive model. Using this model, a few novel principles for energy distribution (e.g. Charge Push Through technique) was developed. In the near future, these techniques are also applicable to the design of versatile sensor systems.

A new primary torque control concept for hydrostatics mobile machines was introduced in 2018 [1]. The mentioned concept controls the pressure in a closed circuit by changing the angle of the hydraulic pump to achieve the desired pressure based on a feedback system. Thanks to this concept, a series of advantages are expected [2]. However, while working in a Y cycle, the primary torque controlled wheel loader has worse performance in efficiency compared to secondary controlled earthmover due to lack of recuperation ability. Alternatively, we use deep learning algorithms to improve machines’ regeneration performance. In this paper, we firstly make a potential analysis to show the benefit by utilizing the regeneration process, followed by proposing a series of CRDNNs, which combine CNN, RNN, and DNN, to precisely detect Y cycles. Compared to existing algorithms, the CRDNN with bidirectional LSTMs has the best accuracy, and the CRDNN with LSTMs has a comparable performance but much fewer training parameters. Based on our dataset including 119 truck loading cycles, our best neural network shows a 98.2 % test accuracy. Therefore, even with a simple regeneration process, our algorithm can improve the holistic efficiency of mobile machines up to 9% during Y cycle processes if primary torque concept is used.

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The introduction of hybrid powertrains has made it possible to utilise unconventional engines as primary power units in vehicles. The free-piston energy converter (FPEC) is such an engine. It is a combination of a free-piston combustion engine and a linear electrical machine. The main features of this configuration are high efficiency and a rapid transient response. In this thesis the free-piston energy converter as part of a hybrid powertrain is studied. One issue of the FPEC is the generation of pulsating power due to the reciprocating motion of the translator. These pulsations affect the components in the powertrain. However, it is shown that these pulsations can be handled by a normal sized DC-link capacitor bank. In addition, two approaches to reduce these pulsations are suggested: the first approach is using generator force control and the second approach is based on phase-shifted operation of two FPEC units. The latter approach results in higher frequency and lower amplitude of the pulsations, which reduce the capacitor losses. The FPEC start-up requirements are analysed and by choosing the correct amplitude of the generator force during start-up the energy consumption can be minimised. The performance gain of utilising the FPEC in a medium sized series hybrid electric vehicle (SHEV) is also studied. An FPEC model suitable for vehicle simulation is developed and a series hybrid powertrain, with the same performance as the Toyota Prius, is dimensioned and modelled. Optimisation is utilised to find a lower limit on the SHEV's fuel consumption for a given drivecycle. In addition, three power management control strategies for the FPEC system are investigated: two load-following strategies using one and two FPEC units respectively and one strategy based on the ideas of an equivalent consumption minimisation (ECM) proposed earlier in the literature. The results show a significant decrease in fuel consumption, compared to a diesel-generator powered SHEV, just by replacing the diesel-generator with an FPEC. This result is improved even more by using two FPEC units to generate the propulsion power, as this increases the efficiency at low loads. The ECM control strategy does not reduce the fuel consumption compared to the load-following strategies but gives a better utilisation of the available power sources. / QC 20101116

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This term project deals with the problem of scheduling real-time tasks in overload conditions and techniques for lowering power consumption. Each of these parts features mechanisms and reasons for their using. There are also described specific algorithms, that are implemented, in operating system uC/OS-II, and compared in next phase of master's thesis.

Les circuits de récupération d'horloge et de données sont nécessaires au bon fonctionnement de plusieurs systèmes de communication sans fil. Les travaux effectués dans le cadre de cette thèse concernent le développement de ces circuits avec d'une part la réalisation, en technologie HCMOS9 0,13 μm de STMICROELECTRONICS, de circuits CDR analogiques à 1 et 54 Mbit/s, et d'autre part, la mise en œuvre de fonctions CDR numériques programmables à bas débit. Un circuit CDR fonctionnant à plus bas débit (1 Mbit/s) a été conçu dans le cadre de la gestion d'énergie d'un récepteur ULB impulsionnel non cohérent. Ces deux structures ont été réalisées à l'aide de PLL analogiques du 3ème ordre. Un comparateur de phase adapté aux impulsions issues du détecteur d'énergie a été proposé dans cette étude. Les circuits ont ensuite été dimensionnés dans le but d'obtenir de très bonnes performances en termes de jitter et de consommation. En particulier, les performances mesurées (sous pointes) du circuit CDR à 1 Mbit/s permettent d'envisager une gestion d'énergie efficace (réduction de plus de 97% de la consommation du récepteur). Dans le cadre d'une chaîne de télémesure avion vers sol, deux circuits CDR numériques ont également été réalisés durant cette thèse. Une PLL numérique du second degré a été implémentée en vue de fournir des données et une horloge synchrone de celles-ci afin de piloter une chaîne SOQPSK entièrement numérique. Un circuit ELGS a également mis au point pour fonctionner au sein d'un récepteur PCM/FM. / Clock and data recovery circuits are required in many wireless communication systems. This thesis is about development of such circuits with: firstly, the realization, in HCMOS9 0.13 μm of STMICROELECTRONICS technology, of 1 and 54 Mb/s analog CDR circuits, and secondly, the implementation of programmable digital circuits at low rates. In the aim of an impulse UWB transceiver dealing with video transmission, a CDR circuit at 54 Mb/s rate has been realized to provide clock signal synchronously with narrow pulses (their duration is about a few nanoseconds) from the energy detector. Another CDR circuit has been built at 1 Mb/s rate in a non-coherent IR- UWB receiver power management context. Both circuits have been implemented as 3rd order analog PLL. In this work, a phase comparator suitable for “RZ low duty cycle” data from the energy detector has been proposed. Circuits have been sized to obtain very good performances in terms of jitter and power consumption. Particularly, measured performances of the 1 Mb/s CDR circuit allow to plan an efficient power management (a decrease of more than 97% of the receiver total power consumption). In the context of a telemetry system from aircraft to ground, two digital CDR circuits have also been implemented. A second order digital PLL has been adopted in order to provide synchronous clock and data to an SOQPSK digital transmitter. Also, a digital ELGS circuit has been proposed to work in a PCM/FM receiver. For both CDR structures, the input signal rate is programmable and varies globally from 1 to 30 Mb/s.

A l’aide de la Représentation Energétique Macroscopique (REM) comme outil de modélisation graphique, la modélisation et la gestion d’énergie d’une application stationnaire isolée à base d’un système PEMFC couplé à l’énergie solaire photovoltaïque comme source principale d’énergie sont développées. Afin d’assurer une autonomie du système en combustible, un électrolyseur PEM est intégré au dispositif. En outre, des packs de batteries et de supercondensateurs permettent un stockage d’énergie et de puissance.Grâce à la modularité de la REM, les modèles respectifs des différentes entités énergétiques du système ont été développés avant de les assembler pour reconstituer un modèle global. Une caractéristique propre de la REM étant la commande, une Structure Maximale de Commande (SMC) est déduite du modèle REM du système par application de règles d’inversion.Le phénomène d’effet échelle a permis de dimensionner le système grâce à un profil de consommation domestique d’énergie électrique. Une stratégie de gestion énergétique basée sur la méthode du bilan des flux de puissance et prenant en compte les dynamiques de chaque source a été développée. Différents modes de fonctionnement ont été étudiés. Grâce è un profil d’ensoleillement d’une journée, la pertinence du modèle a été évaluée. Il a été en outre introduit un couplage entre la méthode du bilan des flux de puissance et la logique floue afin que la stratégie de gestion redéfinisse les références des grandeurs électriques en tenant compte de l’état de charge des batteries et de celui des supercondensateurs. / A stand alone multi-source system based on the coupling of photovoltaic energy and both a PEM electrolyser and a PEMFC for stationary application is studied. The system gathers photovoltaic array as main energy source, ultracapacitors and batteries packs in order to smooth respectively fast and medium dynamic by supplying the load or by absorbing photovoltaic source overproduction. Because of the necessity of fuel availability, especially for islanding application like this one, a PEM electrolyser is integrated to the system for in situ hydrogen production.The main purpose being modeling and management of the power flows in order to meet the energy requirement without power cut, a graphical modeling tool namely Energetic Macroscopic Representation (EMR) is used because of its analysis and control strengths. Thanks to the modular feature of the EMR, the different models of each energetic entity of the system are performed before their assembling.By using scale effect, the energetic system sizing is performed according to a household power profile. Then, by the help of the multi-level representation, the maximal control structure (MCS) is deduced from the system EMR model. The electrical reference values of the MCS are generated by applying the power balancing method involving the own dynamic of each source into the energy management strategy. Different behavior modes are taken into account. By considering an irradiance profile for one day, the system is simulated highlighting its suitable behaviour. Moreover, the relevance of the introduced coupling between fuzzy logic controller and the power balancing method is pointed out.

Energy harvesting is identified as an alternative solution for powering implantable biosensors. It can potentially enable the development of self-powered implants if the harvested energy is properly handled. This development implies that batteries, which impose many limitations, are replaced by miniature harvesting devices. Customized interface circuits are necessary to correct for differences in the voltage and power levels provided by harvesting devices from one side, and required by biosensor circuits from another. This thesis investigates the available harvesting sources within the human body, proposes various methods and techniques for designing power-efficient interfaces, and presents two CMOS implementations of such interfaces. Based on the investigation of suitable sources, this thesis focuses on glucose biofuel cells and thermoelectric harvesters, which provide appropriate performance in terms of power density and lifetime. In order to maximize the efficiency of the power transfer, this thesis undertakes the following steps. First, it performs a detailed analysis of all potential losses within the converter. Second, in relation to the performed analysis, it proposes a design methodology that aims to minimize the sum of losses and the power consumption of the control circuit. Finally, it presents multiple design techniques to further improve the overall efficiency. The combination of the proposed methods and techniques are validated by two highly efficient energy harvesting interfaces. The first implementation, a thermoelectric energy harvesting interface, is based on a single-inductor dual-output boost converter. The measurement results show that it achieves a peak efficiency of 86.6% at 30 μW. The second implementation combines the energy from two sources, glucose biofuel cell and thermoelectric harvester, to accomplish reliable multi-source harvesting. The measurements show that it achieves a peak efficiency of 89.5% when the combined input power is 66 μW. / Energiskörd har identifierats som en alternativ lösning för att driva inplanterbara biosensorer. Det kan potentiellt möjliggöra utveckling av själv-drivna inplanterbara biosensorer. Denna utveckling innebär att batterier, som sätter många begränsningar, ersätts av miniatyriserade energiskördsenheter. Anpassade gränssnittskretsar är nödvändiga för att korrigera för de skillnader i spänning och effektnivå som produceras av de energialstrande enheterna, och de som krävs av biosensorkretsarna. Denna avhandling undersöker de tillgängliga källorna för energiskörd i den mänskliga kroppen, föreslår olika metoder och tekniker för att utforma effektsnåla gränssnitt och presenterar två CMOS-implementeringar av sådana gränssnitt. Baserat på undersökningen av lämpliga energiskördskällor, fokuserar denna avhandling på glukosbiobränsleceller och termoelektriska energiskördare, som har lämpliga prestanda i termer av effektdensitet och livstid. För att maximera effektiviteten hos effektöverföringen innehåller denna avhandling följande steg. Först görs en detaljerad analys av alla potentiella förluster inom boost-omvandlare. Sedan föreslår denna avhandling en designmetodik som syftar till att maximera den totala effektiviteten och effektförbrukningen. Slutligen presenterar den flera designtekniker för att ytterligare förbättra den totala effektiviteten. Kombinationen av de föreslagna metoderna och teknikerna är varierade genom två högeffektiva lågeffekts energigränssnittskretsar. Den första inplementeringen är ett termoelektriskt energiskördsgränssnitt baserat på en induktor, med dubbla utgångsomvandlare. Mätresultaten visar att omvandlaren uppnår en maximal effektivitet av 86.6% vid 30 μW. Det andra genomförandet kombinerar energin från två källor, en glukosbiobränslecell och en termoskördare, för att åstadkomma en tillförlitlig multi-källas energiskördslösning. Mätresultaten visar att omvandlaren uppnår en maximal effektivitet av 89.5% när den kombinerade ineffekten är 66 μW. / <p>QC 20170508</p> / Mi-SoC