As a result of multiple energy sources, hybrid
electric vehicles (HEVs) provide additional flexibility of the
engine operating point, which enables optimization of fuel
economy and emissions reduction. This paper introduces an
energy management (EM) control strategy by an optimal
control approach that jointly optimizes fuel consumption and
various vehicle pollutant emissions. Engine thermal dynamics
are modeled and integrated into the engine-out emission and
fuel consumption models for enhanced modeling accuracy.
The proposed method is formulated as an optimal control
problem (OCP) that is benchmarked against a baseline EM
strategy for fuel consumption only optimization. The proposed
temperature sensitive emission and fuel consumption models
enable a thorough investigation of engine temperature-emissions
relationships, which provide important insights into the optimal
power split during the engine preheating phase. Simulation
results validate the effectiveness of the proposed approach and
highlight the importance of analyzing the fuel consumptionemissions trade-off, as small compromises in fuel consumption
lead to significant reductions in emissions