Research on Modeling and Simulation of SI Engine for AFR Control Ap- plication

Accurate AFR control with TWC is a significant method to reduce the exhaust emission of SI engines. To follow the up to date model-based methodology in automotive industries, a virtual engine simulation platform was carried out to simulate a SGMW B15 engine based on enDYNA and improved by adding the AFR path dynamic models. Experiments and simulation results were compared for the model validation both about the engine performance at steady state, and especially the AFR path transient response. Also a soft ECU model was designed for the control algorithm implementation. Simulation results shows that the engine model is appropriate for simulating SI engine operated at steady and transient state, and the close-loop PID controller has better performance for suppressing the overshoot of AFR signal during transient throttle position varying. The simulation model described in this work could support the AFR control algorithm development as a proper virtual engine control objects.