01628691

Component

The World-wide harmonized Light duty Test Procedure (WLTP) issued as UNECE GTR No. 15 has greatly reduced the flexibilities that are in the New European Driving Cycle (NEDC) procedure and has eliminated many loopholes. However a certain degree of flexibility in the test procedure is necessary, otherwise no type approval test would be valid. After-test corrections can therefore increase the repeatability of the test results and provide CO₂ values that better reflect the target cycle. The work presented in this paper shows the results of the practical implementation of some corrections, such as imbalances in the state of charge (SOC) of the battery; deviations against the target road load; target speed; target distance; and target soak temperature. In summary, all corrections steps performed in this study influenced the average CO₂ emissions by approximately 1.3% and 3.8%, for WLTP and NEDC respectively, which in our opinion is an indication of the reduction of flexibilities from NEDC to WLTP. For analyzing driving behavior during the NEDC and WLTC tests drive trace indices have been computed and reported. Some of them showed promising potential in detecting driving styles that can result in excessive or low fuel economy and subsequently higher or lower CO₂ emissions. Further tests and analyses are needed and warranted for a better understanding of this issue, setting the limits, and possible test corrections.

This paper was sponsored by TRB committee ADC20 Standing Committee on Transportation and Air Quality.

01618707

17-04863

English

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Behavior; Carbon dioxide; Driving; Environmental impacts; Pollutants; Testing

Environment; Highways

Transportation Research Board Annual Meeting 2017 Paper #17-04863

TRIS, TRB, ATRI

Dec 8 2016 11:52AM