Abstract
There is an ongoing need for the investigation of new combustion processes and the development of adequate combustion control strategies. The Institute of Automatic Control and the Institute for Combustion Technology at RWTH Aachen University have investigated modeling and control of new combustion processes such as premixed-charge compression ignition (PCCI). A cascaded control loop that is real-time capable and consists of an underlying model-based air path controller and a model-based combustion controller were successfully applied to a four-cylinder Diesel engine. However, the associated research on real engine test beds is expensive in cost and time. Virtual test beds offer an attractive alternative as they are more efficient and less costly. For this purpose, a realistic virtual test bed of the PCCI diesel engine is set up. The mentioned cascaded control structure is included into the virtual test bed as well. For the representation of the engine combustion, a multi-zone combustion model with inter-zonal mixing and detailed chemistry is applied. The air path is modeled by a dynamic grey-box model, which describes adequately the inlet and exhaust part of the engine. All models and controllers have been implemented in MATLAB/ Simulink. In this way, a realistic environment of a PCCI engine and its periphery was established. Using the virtual test bed, it is possible to validate different combustion models and to pre-parameterize the model-based controller in an effective and cost-conscious manner.
KEYWORDS – Virtual test bed; multi-zone combustion model; model-based control; PCCI; combustion controller