Snyder, K. and Ku, J., "Equivalent Drive Cycle Analysis, Simulation, and Testing - Wayne State University's On-Road Route for EcoCAR2," SAE Technical Paper 2013-01-0549, 2013, doi:10.4271/2013-01-0549.
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.