Towards a Complete Engine Calibration Methodology, Dynamic Design of Experiments (DDoE), Application to Catalyst warm-up phase

In recent years, engine calibration became a very hard task because of the increasing complexity of systems and the severity of the depollution norms regarding Real Driving Emissions (RDE). In particular, optimal engine control during dynamic phases became crucial for reducing pollutant emissions. Beyond the classical engine calibration method based on steady state experiments, methods that integrate the dynamical response of the system constitute therefore a promising approach. This work proposes a global approach of engine dynamical model-based calibration (DMBC) and optimization based on a dynamic Design of Experiments (DDoE). After a description of the general architecture of the calibration process, the paper focuses on the methodology for the design of DDoE. The proposed DDoE is based on an extraction of highly dynamical legal norm cycles (from the analysis of existing RDE cycles), together with variations of control parameters which are intern variables of the control strategy of the engine control unit (ECU). Variation of control parameters allows variation of calibration parameters which are outputs of the control strategy and relevant regarding emissions. An optimization of the efficiency of the DDoE generated is carried out, by simulating driving cycles with different settings of the control strategy. The catalyst warm-up phase has been chosen as an application case of the methodology developed in this paper. The main objective of this phase is to heat the catalyst as fast as possible so that it becomes efficient regarding reduction of pollutant emissions. The first results describe the DDoE that will be next performed in a test bench, in order to model engine emissions. This model will be used as a tool for optimization algorithms to get optimal values of engine calibration parameters by optimizing the control parameters defined in look-up tables structure. Keywords: DDoE, Optimization, RDE, DMBC