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Due to stricter fuel consumption and emissions requirements new gasoline engine concepts using advanced combustion systems such as fully variable valve train and controlled auto-ignition (HCCI) become important. Classical generic methods developed for system optimization with an increased number of variabilities (e.g. DoE - Design of Experiments), need extensions, because closed loop control is required for critical system parameters like valve train actuation and combustion behavior. This paper describes a new approach called “controlled optimization”, which is an extension of DoE using real-time controllers for critical system parameters (e. g. combustion timing). This ensures stable engine operation and protection under all conditions. Less critical parameters are still used as simple DoE-set values. Combustion timing, directly related to spark advance in conventional gasoline engines, is also strongly influenced by valve timing parameters.

Future demands regarding emissions, fuel consumption and driveability lead to complex engine and power train control systems. The calibration of the increasing number of free parameters in the ECU's contradicts the demand for reduced time in the power train development cycle. This paper will focus on the automatic, unmanned closed loop optimization of driveability quality on a high dynamic engine test bed. The collaboration of three advanced methods will be presented: Objective real time driveability assessment, to predict the expected feelings of the buyers of the car Automatic computer assisted variation of ECU parameters on the basis of statistical methods like design of experiments (DoE). Thus data are measured in an automated process allowing an optimization based on models (e.g. neural networks).

Modern Internal Combustion Engines - especially Direct Gasoline Injection engines (DGI) - are equipped with an increasing number of actuators, thus enabling the application of new combustion systems for passenger cars. To fully take advantage of the potential of the combustion system in reducing fuel consumption, it is important to optimize these parameters simultaneously. The methodology using the CAMEO Optimization Tool supports the basic calibration as well as the optimization in the multidimensional room. Further it is important, to provide the knowledge of the engine behavior through out the whole ECU-calibration process.

To meet the future demands on internal combustion engines regarding efficiency emissions and durability all design parameters must be optimized together. As a result of progress in material engineering fuel injection technology turbo charging technology exhaust gas after treatment there arise a multiplicity of possible parameters, such as: design parameters (compression ratio, dimensioning depending on peak firing pressure and mean effective pressure), injection system (rate shaping, split injection, injection pressure, hole diameter), air management (turbo charging with or without VTG, EGR rate) combustion optimization (timing, air access ratio). The interaction of all these parameters can not be over-looked without simulation and optimization tools. This is valid for the concept layout, the optimization and the application process later on.

Rising demands on new engine development require an increasing use of complex engine control systems. The calibration of such complex systems is a time and cost consuming task. Today's engine test bed technique offers full automatic calibration and optimization programs. With such programs engine mapping and calibration can be carried out at reasonable time even when a rising number of parameters is necessary. One important parameter in this field is engine knock. In this paper a new approach for real time knock analysis is described. This new approach allows a high accurate knock detection in the whole engine operation range without any adjustment during an automatic test run. Such a test run with an application of an automatic engine map calibration is presented. The goal for this optimization task was a two dimensional calibration of spark advance and EGR to minimize the NOx + HC emission under the restriction of a defined fuel consumption.

Due to increasing complexity of engine electronic systems, there is a demand to handle the often more than 10,000 calibration data automatically. Establishing optimized start of injection and EGR tables of a TC DI Diesel engine by conventional methods takes about two weeks of intensive calibration work. By automatic map calibration, this task can be handled in less than 20 hours automatically, with no staff required during optimization. The benefits of automatic calibration therefore are reduced costs and faster response to any changes in parameters, even with complex multidimensional engine calibration problems. The paper describes the optimization method as well as the experimental work on the test stand that produces the results.