Explicit Model Predictive Control of the Diesel Engine Fuel Path

For diesel engines, fuel path control plays a key role in achieving optimal emissions and fuel economy performance. There are several fuel path parameters that strongly affect the engine performance by changing the combustion process, by modifying for example, start of injection and fuel rail pressure. This is a multi-input multi-output problem. Linear Model Predictive Control (MPC) is a good approach for such a system with optimal solution. However, fuel path has fast dynamics. On-line optimisation MPC is not the good choice to cope with such fast dynamics. Explicit MPC uses off-line optimisation, therefore, it can be used to control the system with fast dynamics. In this paper a detailed description of explicit MPC for fuel path design has been given and a two-input two-output explicit MPC has been demonstrated to successfully control two outputs of the engine: exhaust temperature, nitrogen oxides (NOx) or particulate matter (PM) emissions with good performance (stability, response and static error) at a single engine operating point.