Methodology Proposal for Emission Tests with Laboratory Simulation of an Urban Drive Route 2005-01-4056
This paper presents a methodology proposed by the PETROBRAS Research Centre (CENPES) to simulate in a laboratory a route performed during field emission tests run with an on-board emission measurement system. It also includes the procedure followed to build the drive cycle and to implement it at the CENPES' Vehicle Test Laboratory.
Laboratory simulation of local urban routes, for instance, allows analyzing the impact of a new fuel formulation on the emission levels of a local fleet with higher accuracy and repeatability, as the test conditions can be better controlled. The usage of on-board emission measurement systems is more expensive and is subject to fluctuations in the traffic conditions, making comparative tests more difficult.
In order to generate the new cycle, data acquired during the field tests was used to determine speed profiles and an average speed distribution was calculated. The cycle was implemented at the laboratory after analyses of the gear shift points, driving behaviour and gas sampling phases.
Emission tests were run following this new cycle, and in this paper their results are evaluated and compared with results obtained when following the Brazilian standard ABNT NBR 6601, used to homologate light duty vehicles in the country. This standard is based on the part 86 of the US CFR Title 40, and uses the EPA 75 drive cycle.