The enviroCar platform offers a broad range of data about traffic that can be used by different stakeholder groups. Fuel consumption is of special interest, e.g. when trying to understand the environmental impact of traffic or when trying to minimize fuel consumption by individual drivers. In enviroCar, there are currently two models to calculate fuel consumption: 1) using motor data from the on-board diagnostics (OBD) and 2) using GPS data from mobile phones running the enviroCar app.
1) OBD-derived fuel consumption
Instantaneous fuel consumption,
Mass density,
Table 1: Parameters used for gasoline and diesel engines.
Gasoline | 745 g/l | 14.7 | 1 |
Diesel | 832 g/l | 14.5 | measured or Eq. |
The air-fuel equivalence ratio,
where
In cases where direct mass-air-flow measurements are not available, it is calculated using Eq.
with the following parameters
2) GPS-based fuel consumption
This load-based model considers the instantaneous power that the motor provides to overcome the driving resistance. Fuel consumption is calculated using Eq.
where
The efficiency considers energy losses through, e.g., heat or friction. Because this highly depends on the driving condition, we use a variable efficiency depending on the driving resistance:
The minimum efficiency,
We introduce the idle power,
At the moment, vehicle-specific properties like vehicle mass or cross-sectional area are defined with some average values. In the future, the enviroCar platform should be extended to provide real values or at least values for different vehicle classes, e.g. light and heavy vehicles.
*Units are defined here as measured or used in the software. Consistent unit conversion is performed when executing the calculations, but not mentioned here for clarity.
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