Modern diesel engines have many variables that affect the vehicle's emission characteristics. The calibration of the control unit that processes these variables is thus essential for emission limit value compliance. Conventional calibration methods are time-intensive, non-systematic and lead in part to sub-optimal results. Within the framework of this project, a universal calibration of the control unit was developed that enables the emission strategy to be changed instantly, even when the engine is running. Parameterised characteristics, which depict all possible emission strategies, form the basis. Model-based virtual emission sensors were also deduced, which can derive these characteristics from the model or also support emission regulation and provide information faster and cheaper than real sensors. With this scientifically verified, user-friendly methodology, the control unit can be optimally set with respect to the purity of diesel engine exhaust gases.
» The demonstrated methodology provides a useful tool for further reducing exhaust gas emissions. Especially in light of the ever increasing complexity of the overall system, the optimised weighting of engine-out emissions and consumption has significant potential. «
The calibration of the control unit of diesel engines enables optimised emission behaviour.
Comparison of the theoretically achievable engine performance (green curve from simulation/optimisation) and the validation measurements on the test stand or individual points on the Pareto-Front.
The engine test bed.
Connection options in the outlet duct downstream of the turbine for determining the raw emissions.
Modern diesel engines are subject to high emission requirements. The control unit processes a number of characteristics that have a considerable influence on the engine-out emissions. Conventional methods for calibrating control units are based on non-systematic, intuitive methods, are disproportionally time-intensive and do not necessarily produce optimal results. The aim of the project was to develop a sound approach for calibration, which taps the engine's entire optimisation potential.
The control-technology part of project focused on the development of a feedback-based emission control system of the engine. All possible emission strategies were computed and clustered according to parameterised characteristics. Tests on an engine test stand served to review the integrated and adapted emission control strategies. In the combustion technology part of the project, everything revolved around virtual emission sensors. These could replace real sensors and thus make available emission information faster and more cheaply.
Measurements on the engine test stand showed that particle and NOx emissions could be reduced by up to 50 per cent with consumption remaining the same, using the new regulation strategy in the New European Driving Cycle (NEDC) as well as in worldwide harmonised test cycles for light vehicles (WLTC). The new emission regulation had no influence on the size distribution of the arising soot particles. Phenomenological models that are based on the physical correlation and describe the emission behaviour (considering all relevant influence factors) were a further important result of the project. They present the virtual emission sensors, the effectiveness of which was also successfully tested on the engine test stand. With these findings it is possible to calibrate the control unit systematically with respect to efficient emission control in the future.
Emissions-optimised Diesel Engine | Measuring and control concepts for diesel engines with virtual NOx and particle matter sensors. Automated set value generation for individually selectable emission strategies. | Project No. 1140
Public & FVV Funding
2013-01-01 to 2015-06-30
1 | Institute for Dynamic Systems and Control (IDSC) | Department of Mechanical and Process Engineering (D-MAVT) | ETH Zurich
Head of Research:
Prof. Dr. Christopher Onder
Dr. Philipp Elbert
Dr. Alois Amstutz
2 | Aerothermochemistry and Combustion Systems Laboratory (LAV) | Institute of Eneregy Technology (IET) | Department of Mechanical and Process Engineering (D-MAVT) | ETH Zurich
Head of Research:
Prof. Dr. Konstantinos Boulouchos
Dr. Christophe Barrofür Aerothermochemie und VerbrennungssystemeLaboratoriums für Aerothermochemie und Verbrennungssysteme
Research Association for Combustion Engines eV
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