Model-based control of torque and nitrogen oxide emissions in a Euro VI 3.0L diesel engine through model-in-the-loop

A model-based technique for the control of BMEP (Brake Mean Effective Pressure) and NOx (Nitrogen Oxide) emissions has been developed and then assessed on a FPT F1C Euro VI diesel engine for light-duty applications. The model-based technique requires the adoption of a predictive combustion model to simulate the heat release rate and BMEP, on the basis of the injection pattern, from which NOx emissions can be calculated. The heat release model is based on the accumulated fuel mass approach which needs as inputs the start of injection of the different pulses and the injected fuel mass quantities. The in-cylinder pressure is then simulated using a single-zone approach. The model-based controller defines the optimal values of SOImain and qf,inj that allow the desired targets of BMEP and NOx to be reached cycle-by-cycle. The controller has been developed and assessed by means of Model-in-the-Loop (MiL), by coupling a fast running engine model developed in GT-Power environment with the combustion controller developed in Simulink environment. Several load ramps for different engine speeds were simulated in MiL to verify the functionality of the controller. The activity was carried out within a research project in collaboration with FPT Industrial. It was shown that the developed algorithm has a good potential in controlling NOx emissions and BMEP and features real-time capability. Therefore, it is suitable for the subsequent implementation on the engine through rapid prototyping.