Wyatt, D., Li, H., and Tate, J., "Examining the Influence of Road Grade on Vehicle Specific Power (VSP) and Carbon Dioxide (CO2) Emission over a Real-World Driving Cycle," SAE Technical Paper 2013-01-1518, 2013, doi:10.4271/2013-01-1518.
The Carbon Dioxide (CO₂) emission from a EURO 3 diesel van over a real-world driving cycle were investigated utilizing part of the Leeds University - Headingly Ring Road (LU-HR) driving cycle, which comprises both an urban (congested) and extra-urban (high speed) driving section.The vehicle used in this research was a 1.8-liter Ford Connect TDCi diesel van. Emissions were monitored by a Portable Emissions Measurement System (PEMS) incorporating an on-board FTIR (Fourier Transform Infrared) exhaust emission measurement system, a Horiba On Board emissions measuring System (OBS 1300) which measured the exhaust flow rate and air/fuel ratio, and a RaceLogic VBOX II differential GPS system provided geographical position, speed and acceleration data.Route topography is known to have substantial influence on vehicle emission. The research reported in this paper was designed to investigate the effect of road grade on the test vehicle's CO₂ emission across a real-world test drive cycle, employing a route elevation profile derived from Digital Elevation Model (DEM) data.Vehicle Specific Power (VSP), representing the instantaneous engine power at each second of the vehicle's transit thorough the test cycle, has been demonstrated in a number of studies as an excellent parameter for modeling CO₂ emission. The VSP calculation in this paper was enhanced through the incorporation of road grade, which was generated by mapping DEM elevation data to each second of measured data recorded in the driving cycle test runs.This study also examines the impact that road grade has on VSP and CO₂ emission over the test cycle using a binning methodology to construct a modal emission estimation model to investigate the vehicle's CO₂ emission at both a mesoscale route and microscale section level.