The Wayne State University (WSU) EcoCAR2 student team is
participating in a design competition for the conversion of a 2013
Chevrolet Malibu into a plug-in hybrid. The team created a
repeatable on-road test drive route using local public roads near
the university that would be of similar velocity ranges contained
in the EcoCAR2 4-Cycle Drive Schedule - a weighted combination of
four different EPA-based drive cycles (US06 split into city and
highway portions, all of the HWFET, first 505 seconds portion of
UDDS).
The primary purpose of the team's local on-road route was to
be suitable for testing the team's added hybrid components and
control strategy for minimizing petroleum consumption and tail pipe
emissions. Comparison analysis of velocities was performed between
seven local routes and the EcoCAR2 4-Cycle Drive Schedule. Three of
the seven local routes had acceptable equivalence for velocity (R₂
≻ 0.80) and the team selected one of them to be the on-road test
drive route.
The secondary purpose was to explore various approaches for
evaluating route equivalence. The EcoCAR2 organizers will create
the competition's private track equivalent route approximation
of the EcoCAR2 4-Cycle Drive Schedule, but this has not been shared
with the teams, so the team was not able to evaluate the
equivalence of the competition route. The team was successful in
evaluating equivalence across various approaches for the team's
local routes. However, the local route analysis showed that
acceleration and average accel/decel had some of the worse
equivalence results.
Drive cycle data was analyzed to compare acceleration
equivalence, city/highway driving mix, average accel/decel, total
road load energy, and simulations were performed for fuel
consumption. Simulations were done due to the team's lack of
chassis dyno test data for the EcoCAR2 4-Cycle Drive Schedule and
the EPA does not publish data for individual drive cycles or
portions of them. The team has not yet been able to do any testing
on a chassis dynamometer or a private track, so local public road
testing was the only test data available. A Driver's Aid for
following a drive cycle trace would greatly help improve
equivalence for vehicle velocity and acceleration.