Driving cycles are acting as the basis of the evaluation of the vehicle performance from air quality point of view, such as fuel consumption or pollutant emission, especially in emission modeling and emission estimation. The original definition of the driving cycle, or drive schedule, given by U.S. Environmental Protection Agency (EPA), is basically a speed-time trajectory which is able to describe the general driving characteristics and driving patterns. Therefore, the development of drive cycles requires a large amount of real data to realize such “generalization”. Then, with such the eligible data collected, it leads to the development of modeling, from traffic modeling to emission modeling, especially for those pollutant emissions which have the public concern.
In this study, focused on heavy duty diesel vehicles (HDDVs), the estimations of the common emissions are being made based on the Texas specific drive cycles, in second-by-second form, collected and generated from five local metropolitan areas, including Houston, Austin, San Antonio, Dallas-Fort Worth and El Paso. First of all, the accurate Global Positioning System (GPS) logging technique is applied for data collection in order to collect not only the moving data but also the relevant geographical information, such as location and roadway, for further analysis. Then, during the progress of data cleaning and data processing, some modifications are made subjectively to improve the deficits of the general methodologies developed by EPA. Afterwards, the specific drive cycles are presented in the format of operating mode distributions, which are also the main part of the input during the emission estimation in Motor Vehicle Emission Simulator (MOVES). Along with all the Texas specific inputs prepared, both the rates and amount of studied emissions are estimated through MOVES. A further comparison is made between the emission rates of default analysis and local analysis to verify the accuracy of MOVES at project level. It is found that the default estimation made by MOVES is accurate for mid-speed cases, at magnitude level. Significant differences happened in low-speed cases and high-speed cases, in which it shows the importance to develop the local drive cycles when estimating the emission rates regionally.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/151147 |
| Date | 16 December 2013 |
| Creators | Gu, Chaoyi |
| Contributors | Zhang, Yunlong, Wang, Bruce, Zitesman, Josias |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | Thesis, text |
| Format | application/pdf |
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