Fuel Economy Benefits of Look-ahead Capability in a Mild Hybrid Configuration

Mild hybrid electric vehicles (HEVs) take some benefits of full HEVs while having lower initial cost and weight, making them a more viable proposition for OEMs looking to enter the hybrid market. The popularization of mild hybrid electric vehicles (HEV) has exposed a new research potential in hybrid energy management. The optimal control of fuel economy in such a configuration is hard to achieve due to its multi-dimensional nature and the absence of future information. The blossoming telematics industry offers the potential to gather future information at relatively low cost through on-board sensing and vehicle-to-vehicle communication systems. In this paper, a novel approach to further fuel consumption minimization of a mild HEV is proposed. The approach is focused on adjusting the by-wire throttle in the vehicle in order to modify forward velocity, as well as controlling the power split between two sources. We show that on a realistic urban drive cycle, the telematic-enabled mild hybrid vehicle with preview of 150 meters can achieve up to 20% fuel saving compared to a comparable baseline conventional powertrain vehicle, and a further 1% fuel saving relative to previously published algorithms. The potential for further improvement in fuel economy through optimizing the use of the electric motor is also discussed.