Model based control for a modern automotive diesel engine

The dynamic performance of a turbocharged diesel engine during transient operation has been studied. For appropriate analysis of data obtained from engine transient operation, four alternative automated filtering methods were implemented on the cycle-by-cycle in-cylinder pressure. The techniques to process instantaneous emission data and align the transient data from different analyzers were developed. In the experimental study, the effects of engine speed and EGR have been investigated through load increase tests at a constant engine speed with different EGR calibrations. Based on the experimental results, a real-time diesel engine model was developed by Simulink. The model is capable of simulating the main engine parameters. It included the air path mode], combustion model and dynamic emission behavior model. The model can run as a real-time simulator for engine control strategy development. . An advanced fast predictive contro] approach was proposed and validated in a HIL simulation platform. The model predictive control was developed for EGR and VGT control. The oxygen concentration oriented control was designed and implemented in the real-time model. Compared with PID control, MPC presents a good tracking performance of reference values with a shorter response time. The results in HIL proved the real-time capability of the control strategy

Employment of Real-Time/FPGA Architectures for Test and Control of Automotive Engines

Nowadays the production of increasingly complex and electrified vehicles requires the implementation of new control and monitoring systems. This reason, together with the tendency of moving rapidly from the test bench to the vehicle, leads to a landscape that requires the development of embedded hardware and software to face the application effectively and efficiently. The development of application-based software on real-time/FPGA hardware could be a good answer for these challenges: FPGA grants parallel low-level and high-speed calculation/timing, while the Real-Time processor can handle high-level calculation layers, logging and communication functions with determinism. Thanks to the software flexibility and small dimensions, these architectures can find a perfect collocation as engine RCP (Rapid Control Prototyping) units and as smart data logger/analyser, both for test bench and on vehicle application. Efforts have been done for building a base architecture with common functionalities capable of easily hosting application-specific control code. Several case studies originating in this scenario will be shown; dedicated solutions for protype applications have been developed exploiting a real-time/FPGA architecture as ECU (Engine Control Unit) and custom RCP functionalities, such as water injection and testing hydraulic brake control

Real-time implementation of a sensor validation scheme for a heavy-duty diesel engine

With ultra-low exhaust emissions standards, heavy-duty diesel engines (HDDEs) are dependent upon a myriad of sensors to optimize power output and exhaust emissions. Apart from acquiring and processing sensor signals, engine control modules should also have capabilities to report and compensate for sensors that have failed. The global objective of this research was to develop strategies to enable HDDEs to maintain nominal in-use performance during periods of sensor failures. Specifically, the work explored the creation of a sensor validation scheme to detect, isolate, and accommodate sensor failures in HDDEs. The scheme not only offers onboard diagnostic (OBD) capabilities, but also control of engine performance in the event of sensor failures. The scheme, known as Sensor Failure Detection Isolation and Accommodation (SFDIA), depends on mathematical models for its functionality. Neural approximators served as the modeling tool featuring online adaptive capabilities. The significance of the SFDIA is that it can enhance an engine management system (EMS) capability to control performance under any operating conditions when sensors fail. The SFDIA scheme updates models during the lifetime of an engine under real world, in-use conditions. The central hypothesis for the work was that the SFDIA scheme would allow continuous normal operation of HDDEs under conditions of sensor failures. The SFDIA was tested using the boost pressure, coolant temperature, and fuel pressure sensors to evaluate its performance. The test engine was a 2004 MackRTM MP7-355E (11 L, 355 hp). Experimental work was conducted at the Engine and Emissions Research Laboratory (EERL) at West Virginia University (WVU). Failure modes modeled were abrupt, long-term drift and intermittent failures. During the accommodation phase, the SFDIA restored engine power up to 0.64% to nominal. In addition, oxides of nitrogen (NOx) emissions were maintained at up to 1.41% to nominal

Development of an integrated experimental and numerical methodology for the performance analysis of multiple hybrid electric architectures over different driving cycles

L'abstract è presente nell'allegato / the abstract is in the attachmen

Optisen, yksisylinterisen tutkimusmoottorin ohjaus- ja mittausjärjestelmä

Tämä diplomityö tehtiin osana projektia, jossa rakennettiin yksisylinterinen optinen tutkimusmoottori. Tutkimusmoottorilla tutkitaan matalalämpötilapalamista, jolla voidaan saavuttaa erittäin alhaiset päästöt. Uusi moottori mahdollistaa tähän tarvittavien tekniikoiden käytön. Tekniikoita ovat esimerkiksi esisekoituspalaminen ja pakokaasujen takaisinkierrätys. Moottorilla voidaan myös tutkia kaasun ja polttoaineen sekoittumista sekä palotapahtumaa käyttäen laserkuvantamislaitteita. CFD- laskentaa käytetään näiden tapahtumien teoreettiseen tarkasteluun ennen koeajoja. Diplomityössä rakennettiin tutkimusmoottorille ohjaus- ja mittausjärjestelmä. Järjestelmä perustuu reaaliaikatietokoneeseen, jossa on nopeat mittaus- ja ulostulokortit, sekä käyttöliittymätietokoneeseen. Tässä työssä esitellään ohjaus- ja mittausjärjestelmän toteutus. Valmiin järjestelmän tulee olla helppo ja turvallinen käyttää. Sen pitää olla myös tarpeeksi monipuolinen, jotta sillä voidaan toteuttaa niin optisia mittauksia kuin tavallisia moottorikokeitakin. Kokeellinen osuus työstä keskittyy ohjaus- ja mittausjärjestelmän koestukseen. Kaikki osajärjestelmät sekä koko järjestelmä todettiin toimivan kuten pitääkin. Osia ohjaus- ja mittausjärjestelmästä voitaisiin kuitenkin tutkia ja kehittää vielä lisää

Knock: A Century of Research

Knock is one of the main limitations on increasing spark-ignition (SI) engine efficiency. This has been known for at least 100 years, and it is still the case today. Knock occurs when conditions ahead of the flame front in an SI engine result in one or more autoignition events in the end gas. The autoignition reaction rate is typically much higher than that of the flame-front propagation. This may lead to the creation of pressure waves in the combustion chamber and, hence, an undesirable noise that gives knock its name. The resulting increased mechanical and thermal loading on engine components may eventually lead to engine failure. Reducing the compression ratio lowers end-gas temperatures and pressures, reducing end-gas reactivity and, hence, mitigating knock. However, this has a detrimental effect on engine efficiency. Automotive companies must significantly reduce their fleet carbon dioxide (CO2) values in the coming years to meet targets resulting from the 2015 Paris Agreement. One path towards meeting these is through partial or full electrification of the powertrain. However, the vast majority of automobiles in the near future will still feature a gasoline-fueled SI engine; hence, improvements in combustion engine efficiency remain fundamental. As knock has been a key limitation for so long, there is a huge amount of literature on the subject. A number of reviews on knock have already been published, including in recent years. These generally concentrate on current understanding and status. The present work, in contrast, aims to track the progress of research on knock from the 1920s right through to the present day. It is hoped that this can be a useful reference for new and existing researchers of the subject and give further weight to occasionally neglected historical activity, which can still provide important insights today

Semi-Physical Real-Time Models with State and Parameter Estimation for Diesel Engines

Increasing requirements for the reduction of fuel consumption (CO2) and emissions require a precise electronic management of combustion engines. Engine-related measures to meet these requirements lead to an increase in variability and system complexity. To cope with increasing system complexity, model-based development methodology has proven effective. In this context, virtual development with real-time models plays an increasingly important role. The corresponding models can either be derived theoretically on the basis of known physical laws (white-box models) or obtained experimentally on the test bench by mathematically modeling the measured input and output behavior (black-box models). Both types of modeling have their advantages and disadvantages. A semi-physical modeling methodology is presented that combines the advantages of theoretical and experimental modeling and overcomes their disadvantages. The goal is to find suitable, simplified equation structures and to determine their unknown parameters experimentally by real-time capable, recursive parameter estimation methods. This leads to physically interpretable real-time models that are able to adapt their parameters according to the current engine operating behavior and thus offer good transferability to other engines. The semi-physical modeling methodology is applied to the air system and combustion of a common rail diesel engine with a variable exhaust gas turbocharger and high- and low-pressure exhaust gas recirculation. The focus lies on the derivation of semi-physical real-time model for the combustion and its underlying processes inside the cylinder. A semi-physical model approach for modeling the dynamics of combustion chamber processes is developed and combined with state and parameter estimation methods. This model approach enables crank angle-resolved calculation of the in-cylinder gas states and the determination of the characteristic combustion components of diesel combustion (premixed, diffusive combustion and burn-out). The technical implementation is realized close to the pressure indication system of the engine test bench, enabling a crankshaft-resolved model adaptation based on measured in-cylinder pressure. Model identification is performed using combined state and parameter estimation in steady-state engine operation. Model parameters are estimated perpetually for each duty cycle and converge to a constant value within 30-60 engine duty cycles. Final estimation results are stored as functions of engine operating point using experimental modeling. In this way, semi-physical real-time models are created directly online during the measurement. The treated method is considered as an extension of the functionality of conventional pressure indication systems. Furthermore, the derived semi-physical models are used for real-time engine simulation in the context of hardware-in-the-loop testing of ECUs. The research project (Project No. 1231) was financially and advisory supported by the Research Association for Combustion Engines (FVV) e.V. (Frankfurt am Main, Germany)

Analysis of Advanced Air and Fuel Management Systems for Future Automotive Diesel Engine Generations

The increasing stringency of pollutant emissions regulations, aiming to fuel neutral NOx limits, is expected to foster the implementation of new technologies in terms of aftertreatment, air management and fuel injection systems. In this field, modern diesel engines are equipped with electronically-controlled flexible fuel injection systems and air/gas/EGR control valves. The only part in the air system ‘left for revolutionary’ is the valvetrain and a fully flexible Variable Valve Actuation (VVA) is becoming nowadays highly desirable for modern diesel engine. In this context, the purpose of the research activity was, on one hand, to evaluate and identify, through numerical simulation, the best VVA strategies to be implemented in a passenger car diesel engine by quantifying and choosing benefits vs drawbacks of VVA strategies. On the other hand, the definition of the best injection pattern for BSFC, Emission and NVH improvements through the adoption of Genetic Algorithm was performed. The EURO VI medium diesel engine (1.6 l 4L) developed by General Motors Global Propulsion Systems was selected as case study

Environmental impact of passenger ships in port

The environmental impact of ships can be of different types. This thesis covers air pollution due to chemicals and concentrates on local effects due to compounds emitted in the exhaust gases of internal combustion engines and acoustic pollution. The attention has been focused on the consequences of the presence of many ships in ports located close to inhabited zones. For port-scale analyzes, the case study is the port of Naples for which traffics, geographic conformation, meteorological conditions, results of experimental campaigns both in the field of acoustic and environmental impact are available. In the field of polluting emissions, the case study for the simulations is a catamaran in service at the port of Naples for which experimental measurements at sea and bench tests are available. For the simulation of acoustic emissions, the case study is a passenger ship for which experimental measurements and forecast data are available. Experimental campaigns and simulations have been carried out on the port of Naples and most of the applications concern passenger ships, but methods and procedures can be applied to a general case. The thesis consists of six chapters, briefly introduced here. Each chapter contains a first subsection named "aims and scope" precisely to describe its main purposes in a more extended way than the summary presented here. The theme is first framed in the more general context of the environmental impact of anthropogenic activities and of marine transportation in particular assessment studies and documents issued by international bodies reporting targets for limiting the global environmental impact of the shipping sector are briefly summarized. Recalls on the main mechanisms of formation and reduction of pollutants are exposed. The second chapter describes the bottom-up method aimed at estimating the emissions of passenger ships in port. To obtain an estimation of all the emissions a series of very specific steps are necessary. The main information to be collected and produced concerns: traffic, routes, arrival and departure schedules, engine loads, emissions, heights, and diameters of the funnels. The technique of data collection and its use was gradually deepened (from simple cruise calendar to AIS data). The main application on the entire port sees the use of AIS data. The starting AIS data have been processed through an "ad hoc" MATLAB code capable of managing a relevant amount of data and returning a complete calendar of all the movements of every ship arriving and operating in the port. The use of AIS data has brought about improvements in the calculation methodology for emissions as well, allowing for example a more accurate analysis of average speeds in port and idle times. The port of Naples, where all the analysis were developed, is presented next. The traffics for the years and reference periods chosen in the subsequent analyzes are presented (2012, 2016, and 2018). A comprehensive study of the environmental impact of ships cannot be separated from the creation of atmospheric dispersion models. These models require the flow of pollutants emitted in the main operational phases in port (navigation, maneuvering, and mooring) as the main inputs. The results allow to estimate the weight that the passenger branch has on air quality also thanks to cross-comparisons with port measurements and ARPAC (Regional Agency for Environmental Protection in Campania) data. After the analysis of the environmen0tal impact on a port scale, the problem of emissions has been approached by applying a designated simulation, with the aim to overcome the use of emission factors. The first part of the chapter describes a state of the art of simulation model and an in-depth analysis of the main emission simulation methodologies. An engine model has been created in RICARDO WAVE environment; this engine model was validated and calibrated on an engine installed onboard a passenger ship operating in the port of Naples. Bench test results in terms of power, torque, consumption, and rpm have been used to calibrate the model while experimental measurements validated it. In the dissertation, a description of the case study (ship, engine, bench tests, and sea trials), a description of the model, and an interpretation of the results are presented. The validation on sea trials shows the effectiveness of the model both in terms of main engine parameters and emissions. At the end of the chapter, a comparison between the three emission estimation methodologies (EMEP-EEA, with AIS data, simulations, and experimental campaign) has been carried out. The next chapter of the thesis concerns the assessment of the acoustic impact of passenger ships in port. The structure of the research is typically the same: simulation and experimental results. The first part shows some experimental surveys made on a passenger ship in port that served as validation of a simulation model built in the TERRAIN OLIVE TREE LAB SUITE environment. The second and last part presents the methodology and results obtained in the context of a collaborative research project between the Universities of Naples, Genoa, and Trieste. The project aimed at characterizing the acoustic impact of a ship in light of the new additional class notation published by the Lloyds Register "Procedure for the Determination of Airborne Noise Emissions from Marine Vessels Airborne Noise Emissions from Marine Vessels". The last chapter sets out three applications in order to keep the problem set in a global scale context. The first presents an analysis of the possible countermeasures that can be applied to the cruise ship fleet aimed at environmental safeguarding (DNV Appraisal Tool), in the wake of the EEOI and EEDI. Furthermore, in the context of the environmental impact on a port scale, preliminary measurements of polluting emissions using remote measurement instruments (LIDAR) were carried out with the aim of allowing an indirect estimate of the concentrations of pollutants in the exhausts of ships, thus significantly reducing the uncertainties related to ground-level measurements with active or passive samplers. The last application, on the other hand, concerns the ports and the possible activities and initiatives to be implemented in order to host fleet of increasingly green and eco-sustainable ships (Environmental Ship Index)