999 resultados para Elica, motore elettrico, sensori, banco prova
Resumo:
This work describes the development of a simulation tool which allows the simulation of the Internal Combustion Engine (ICE), the transmission and the vehicle dynamics. It is a control oriented simulation tool, designed in order to perform both off-line (Software In the Loop) and on-line (Hardware In the Loop) simulation. In the first case the simulation tool can be used in order to optimize Engine Control Unit strategies (as far as regard, for example, the fuel consumption or the performance of the engine), while in the second case it can be used in order to test the control system. In recent years the use of HIL simulations has proved to be very useful in developing and testing of control systems. Hardware In the Loop simulation is a technology where the actual vehicles, engines or other components are replaced by a real time simulation, based on a mathematical model and running in a real time processor. The processor reads ECU (Engine Control Unit) output signals which would normally feed the actuators and, by using mathematical models, provides the signals which would be produced by the actual sensors. The simulation tool, fully designed within Simulink, includes the possibility to simulate the only engine, the transmission and vehicle dynamics and the engine along with the vehicle and transmission dynamics, allowing in this case to evaluate the performance and the operating conditions of the Internal Combustion Engine, once it is installed on a given vehicle. Furthermore the simulation tool includes different level of complexity, since it is possible to use, for example, either a zero-dimensional or a one-dimensional model of the intake system (in this case only for off-line application, because of the higher computational effort). Given these preliminary remarks, an important goal of this work is the development of a simulation environment that can be easily adapted to different engine types (single- or multi-cylinder, four-stroke or two-stroke, diesel or gasoline) and transmission architecture without reprogramming. Also, the same simulation tool can be rapidly configured both for off-line and real-time application. The Matlab-Simulink environment has been adopted to achieve such objectives, since its graphical programming interface allows building flexible and reconfigurable models, and real-time simulation is possible with standard, off-the-shelf software and hardware platforms (such as dSPACE systems).
Resumo:
Combustion control is one of the key factors to obtain better performances and lower pollutant emissions for diesel, spark ignition and HCCI engines. An algorithm that allows estimating, as an example, the mean indicated torque for each cylinder, could be easily used in control strategies, in order to carry out cylinders trade-off, control the cycle to cycle variation, or detect misfires. A tool that allows evaluating the 50% of Mass Fraction Burned (MFB50), or the net Cumulative Heat Release (CHRNET), or the ROHR peak value (Rate of Heat Release), could be used to optimize spark advance or to detect knock in gasoline engines and to optimize injection pattern in diesel engines. Modern management systems are based on the control of the mean indicated torque produced by the engine: they need a real or virtual sensor in order to compare the measured value with the target one. Many studies have been performed in order to obtain an accurate and reliable over time torque estimation. The aim of this PhD activity was to develop two different algorithms: the first one is based on the instantaneous engine speed fluctuations measurement. The speed signal is picked up directly from the sensor facing the toothed wheel mounted on the engine for other control purposes. The engine speed fluctuation amplitudes depend on the combustion and on the amount of torque delivered by each cylinder. The second algorithm processes in-cylinder pressure signals in the angular domain. In this case a crankshaft encoder is not necessary, because the angular reference can be obtained using a standard sensor wheel. The results obtained with these two methodologies are compared in order to evaluate which one is suitable for on board applications, depending on the accuracy required.
Resumo:
Il tema generale di ricerca oggetto della presente trattazione è rappresentato dal diritto di difesa nel procedimento de libertate. Esso costituisce un tema da sempre controverso, materia di vivaci e mai sopiti dibattiti sia in dottrina che in giurisprudenza, poiché si colloca in un punto nevralgico non solo del procedimento penale, ma, addirittura, dell’intero ordinamento giuridico di uno stato, poiché in esso si incontrano, e sovente si scontrano, le istanze di garanzia del cittadino contro indebite limitazioni ante iudicium della libertà personale, da un lato, e le esigenze di tutela della collettività e del processo dai pericula libertatis (inquinamento delle prove, rischio di fuga, pericolo di reiterazione dei reati), dall’altro. Detto in altri termini, il procedimento de libertate è esattamente il luogo in cui un ordinamento che voglia definirsi liberale, nella sua naturale e incessante evoluzione, tenta faticosamente di trovare un equilibrio tra autorità e libertà. Trattandosi, per ovvie ragioni, di un argomento vastissimo, che spazia dall’esercizio del diritto di difesa nella fase applicativa delle misure cautelari personali, alle impugnazioni delle misure medesime, dalla revoca o sostituzione delle stesse al giudicato cautelare sulle decisioni de libertate, etc., il campo della ricerca è stato circoscritto a due temi specifici che interessano direttamente il diritto di difesa, limitatamente alla fase dell’applicazione delle misure cautelari personali, e che presentano profili di originalità, per alcune importanti modifiche intervenute a livello sia di legislazione ordinaria che di legislazione costituzionale: 1) l’accertamento dei gravi indizi di colpevolezza; 2) il principio del contraddittorio nel procedimento cautelare, alla luce dell’art. 111 Cost. Siffatti temi, apparentemente disomogenei, sono, in realtà, profondamente correlati tra loro, rappresentando, per usare una locuzione spicciola, l’uno la “sostanza” e l’altro “la forma” del procedimento de libertate, ed insieme concorrono ad individuare un modello di giusto processo cautelare.