  Connected and automated vehicles (CAVs) have been recognized as providing
unprecedented opportunities for substantial fuel economy improvement through
CAV-based vehicle speed trajectory optimization (eco-driving). At the same
time, the implications of the CAV operation on thermal responses, including
those of engine and exhaust aftertreatment system, have not been fully
investigated. To this end, firstly, a sequential optimization framework for
vehicle speed trajectory planning and powertrain control in hybrid electric
CAVs is proposed in this paper. Next, the impact of eco-driving and power split
optimization on the engine and catalytic converter thermal responses, as well
as on the tailpipe emissions is characterized. Despite an average 16%
improvement in fuel economy through sequential optimization, this study shows
that eco-driving slows down the thermal responses, which could unfavorably
affect the tailpipe emissions.
