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del Re, Luigi
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Fast Hybrid Sensor for Soot of Production CI Engines

Johannes Kepler University Linz-Zhen Zhang, Luigi del Re, Richard Fuerhapter
Published 2017-09-04 by SAE International in United States
During transients, engines tend to produce substantially higher peak emissions like soot - the main fraction of particular matter (PM) - which are the longer the more important as the steady state emissions are better controlled. While Diesel particulate filters are normally able to block them, preventing their occurrence would of course be more important. In order to achieve this goal, however, they must be measurable. While for most emissions commercial sensors of sufficient speed and performance are available, the same is not true for PMs, especially for production engines. Against this background, in the last years the possible use of a full stream 50Hz sensor based on Laser Induced Incandescence (LII) was investigated, and the results were very encouraging, showing that the sensor could recognize transient changes undetected by conventional measurement systems (like the AVL Opacimeter) but confirmed by the analysis of combustion. This was also related to the position of the sensor which can be mounted upstream or downstream of the turbine in a turbocharged CI engine. The measurement is instantaneous, without dilution…
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Analysis and Choice of Input Candidates for a Virtual NOx Sensor by a Mutual Information Approach

SAE International Journal of Engines

BMW Motoren GmbH-Bernhard Ramsebner, Christoph Reiter
Johannes Kepler University Linz-Patrick Schrangl, Roman Schmied, Stephan Stadlbauer, Harald Waschl, Luigi del Re
  • Journal Article
  • 2016-01-0957
Published 2016-04-05 by SAE International in United States
Abatement and control of emissions from passenger car combustion engines have been in the focus for a long time. Nevertheless, to address upcoming real-world driving emission targets, knowledge of current engine emissions is crucial. Still, adequate sensors for transient emissions are seldom available in production engines. One way to target this issue is by applying virtual sensors which utilize available sensor information in an engine control unit (ECU) and provide estimates of the not measured emissions. For real-world application it is important that the virtual sensor has low complexity and works under varying conditions. Naturally, the choice of suitable inputs from all available candidates will have a strong impact on these factors. In this work a method to set up virtual sensors by means of design of experiments (DOE) and iterative identification of polynomial models is augmented with a novel input candidate selection strategy. Therefore, a systematic approach to analyze and determine possible input candidates based on mutual information (MI) analysis is introduced. As application example a virtual NOx sensor for a passenger car Diesel…
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A Framework for Virtual Testing of ADAS

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

Automotive Testing Inc-Helmut Kokal
Johannes Kepler University Linz-Jinwei Zhou, Roman Schmied, Alexander Sandalek, Luigi del Re
  • Journal Article
  • 2016-01-0049
Published 2016-04-05 by SAE International in United States
Virtual testing of advanced driver assistance systems (ADAS) using a simulation environment provides great potential in reducing real world testing and therefore currently much effort is spent on the development of such tools. This work proposes a simulation and hardware-in-the-loop (HIL) framework, which helps to create a virtual test environment for ADAS based on real world test drive. The idea is to reproduce environmental conditions obtained on a test drive within a simulation environment. For this purpose, a production standard BMW 320d is equipped with a radar sensor to capture surrounding traffic objects and used as vehicle for test drives. Post processing of recorded GPS raw data from the navigation system using an open source map service and the radar data allows an exact reproduction of the driven road including other traffic participants. The proposed framework automatically generates the recorded and post processed environment within the simulation and enables testing of ADAS strategies by identification and implementation of a detailed vehicle model of the test vehicle. Further, connection of the simulation environment to an engine…
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Short Term Prediction of a Vehicle's Velocity Trajectory Using ITS

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

Johannes Kepler University Linz-Dominik Moser, Harald Waschl, Roman Schmied, Hajrudin Efendic, Luigi del Re
  • Journal Article
  • 2015-01-0295
Published 2015-04-14 by SAE International in United States
Modern cars feature a variety of different driving assistance systems, which aim to improve driving comfort and safety as well as fuel consumption. Due to the technical advances and the possibility to consider vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication, cooperative adaptive cruise control (CACC) strategies have received significant attention from both research and industrial communities.The performance of such systems can be enhanced if the future velocity of the surrounding traffic can be predicted. Generally, human driving behavior is a complex process and influenced by several environmental impacts. In this work a stochastic model of the velocity of a preceding vehicle based on the incorporation of available information sources such as V2I, V2V and radar information is presented. The main influences on the velocity prediction considered in this approach are current and previous velocity measurements and traffic light signals. For practical applications a model must capture the driver's reaction on the traffic situation as well as the vehicle dynamics. Here a Bayesian network approach is followed which provides a compact representation of the variable dependencies and…
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Adaptive SCR Model for MPC Control Including Aging Effects

Johannes Kepler University Linz-Stephan Stadlbauer, Harald Waschl, Luigi del Re
Published 2015-04-14 by SAE International in United States
The focus in the development of modern exhaust after treatment systems, like the Diesel Oxidation Catalyst (DOC), the Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR), is to increase on one hand the oxidation rates of Carbon monoxide (CO), HC (Hydro Carbons) and NO (Nitrogen Oxide) and on the other hand the reduction rates of Particulate Matter (PM) and the NOx emissions to fulfill the more and more restricting requirements of the exhaust emission legislation.The simplest, practical most relevant way to obtain such a dosing strategy of a SCR system is the use of a nonlinear map, which has to be determined by extensive calibration efforts. This feedforward action has the advantage of not requiring a downstream NOx sensor and can achieve high conversion efficiency under steady-state operating conditions for nominal systems. However, such an open-loop approach leads to suboptimal conversion efficiency during transient operation condition and in the presence of system variations (e.g. aging, doser variation). Hence, feedback information and an adaptation criterion for an appropriate SCR life time control is an essential…
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Pressure Based Virtual Sensing of Transient Particulate Matter of CI Engines

SAE International Journal of Engines

Johannes Kepler University Linz-Zhen Zhang, Stephan Stadlbauer, Harald Waschl, Richard Fuerhapter, Luigi del Re
  • Journal Article
  • 2015-01-1635
Published 2015-04-14 by SAE International in United States
At the moment, no equipment is available for fast measurements of particulate matter (PM) from production CI engines, especially during transients. Against this background, virtual sensors may be an option, provided their precision can be validated. This paper presents a new approach to estimate PM emission based only on in-cylinder pressure data. To this end, an in-cylinder pressure trace is measured with a high resolution (0.5 CAD) and every trace is divided into 8 segments according to critical cylinder events (e.g. opening of the valves or the beginning of injection). A piecewise principle component analysis (PCA) is used to compress the information. This information is then used for PM estimation via a second order polynomial model structure. The key element is the separate use of pressure trace information before and during the early stages of combustion. The model is parameterized by steady points and transient experiments which include parts of the FTP and the NEDC. In order to confirm the model quality, the remaining parts of these transient cycles and a randomly generated transient cycle…
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A Simplified Fuel Efficient Predictive Cruise Control Approach

Johannes Kepler University Linz-Roman Schmied, Harald Waschl, Luigi del Re
Published 2015-04-14 by SAE International in United States
Adaptive cruise control (ACC) systems allow a safe and reliable driving by adapting the velocity of the vehicle to velocity setpoints and the distance from preceding vehicles. This substantially reduces the effort of the driver especially in heavy traffic conditions. However, standard ACC systems do not necessarily take in account comfort and fuel efficiency. Recently some work has been done of the latter aspect. This paper extends previous works for CI engines by incorporating a prediction model of the surrounding traffic and a simplified control law capable for real time use in experiments. The prediction model itself uses sinusoidal functions as the traffic measurements often show periodic behavior and is adapted in every sample instant with respect to the predecessor's velocity.Furthermore, the controlled vehicle is forced to stay within a specific inter-vehicle distance corridor to avoid collisions and ensure safe driving. The main advantage of the proposed approach is a simple and fast real time capable implementation, not only for a specific engine type but for a wide range of engines. Simulation and experimental results…
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Dynamic Injection Adaptation by Input Shaping for Low NOx Emissions during Transients

BMW Motoren GmbH-Michael Schinnerl
Johannes Kepler Univ. Linz-Harald Waschl, Luigi del Re
Published 2014-04-01 by SAE International in United States
Especially in view of more and more stringent emission legislation in passenger cars it is required to reduce the amount of pollutants. In the case of Diesel engines mainly NOx and PM are emitted during engine operation. The main influence factors for these pollutants are the in-cylinder oxygen concentration and the injected fuel amount. Typically the engine control task can be divided into two separate main parts, the fuel and the air system. Commonly air system control, consisting of a turbocharger and exhaust gas recirculation control, is used to provide the required amount of oxygen and address the emission targets, whereas the fuel is used to provide the desired torque. Especially in transient maneuvers the different time scales of both systems can lead to emission peaks which are not desired.Against this background in this work instead of the common way to address the air system, the fuel system is considered to reduce emission peaks during transients. The idea is to start from a base calibration and adapt the injection parameters, like start and amount of…
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NO/NO2 Ratio based NH3 Control of a SCR

Johannes Kepler University Linz-Stephan Stadlbauer, Harald Waschl, Luigi del Re
Published 2014-04-01 by SAE International in United States
The emissions of modern Diesel engines, which are known to have various health effects, are beside the drivers torque demands and low fuel consumptions one of the most challenging issues for combustion and after treatment control. To comply with legal requirements, emission control for heavy duty engines is not feasible without additional hardware, usually consisting of a Diesel oxidation catalyst (DOC), a Diesel particulate filter (DPF) and a selective catalytic reduction (SCR) system. In contrast to other NOx reduction systems, e.g. lean NOx traps, the SCR system requires an additional ingredient, namely ammonia (NH3), to reduce the NOx emissions to non harmful components. Consequently, the correct amount of NH3 dosing in the SCR catalyst is one of the critical components to reach high conversion rates and avoid ammonia slip.Against this background and in contrast to existing proposals in which the NH3 dosing is often calculated based on a NOx emission sensor, this work presents a strategy to adopt the set point estimation of the NH3 dosing, based on a virtual NOx sensor extended by a…
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Grey Box Control Oriented SCR Model

Johannes Kepler University Linz-Gabriele Zanardo, Stephan Stadlbauer, Harald Waschl, Luigi del Re
Published 2013-09-08 by SAE International in United States
Although SCR is a well established technology for many applications, it is still a field in which several new approaches and components are being tested. Control is a critical issue, as the conflicting requirements of NOx abatement and very small NH3 slip need to be met. Besides empirical solutions, model based controls have been proposed and are probably the technology of choice, also in view of the combination with monitoring functions. However, SCR models are typically based on First Principles (FP), i.e. on global chemical equations and reaction rate equations, and require precise calibration. Still, their performance for the control of dynamic processes is limited, or a high detail, much a priori information, e.g. on the actual SCR reaction rates, are needed. Frequently, this information is not available or reliable, and this is particularly true when components are changed or modified during the development process, so that typically a re-design is needed.Against this background, this paper proposes a grey box approach, in which a simple first principle model is used as basic model, without assuming…
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