Injection quantity control for GDI engines

To improve fuel economy and reduce emissions, direct injection technology with precise fuel injections is widely used for gasoline engines, because quantitative precise fuel injection, as well as multi injection during one combustion revolution, is fit for the whole engine speed range. This paper designs a PID controller of fuel injection quantity for gasoline direct injection (GDI). Firstly, a mathematical model of an injector, which is used for controller validation, is established mainly based on fluid dynamic; Secondly, a map of fuel injection quantity corresponding with engine demands (according to engine speed and rail pressure) is calibrated by using the high-fidelity engine software enDYNA through experiments. Then, a PID controller is aimed to track the given value of fuel injection quantity. Tuning controller parameters are chosen by randomized algorithm according to the criteria of performance. Simulation results show that the designed control scheme is effective.