Annex 4 analytical methods

model description

general description

acronym
VECTO
name
Vehicle Energy Consumption calculation TOol
main purpose
VECTO is a vehicle simulation software created to support CO2 emissions monitoring from Heavy Duty Vehicles (HDV) in Europe and serve as the official CO2 calculation tool in the certification scheme.
homepage
https://ec.europa.eu/clima/policies/transport/vehicles/vecto_en

Developer and its nature

ownership
EU ownership (European Commission)
ownership additional info
The model was developed by Technical University of Graz and Ricardo AEA on behalf of the JRC and DG CLIMA. The Commission holds the IPR. The model is licenced under EUPL 1.2.
is the model code open-source?
YES - The source code, the users manual and the technical annex regarding VECTO are public by law.

Model structure and approach with any key assumptions, limitations and simplifications

details on model structure and approach

The VECTO vehicle simulation model is used for Heavy Duty Vehicle CO2 and fuel consumption certification in Europe.

The model needs detailed input on a large variety of vehicle subsystems, especially rolling resistance, air drag and transmission data, as well as an engine map. Generic models are available for a number of subsystems, but further development is bringing in more detail, as requested by the industry. 

Given the input data for a base vehicle, VECTO is capable of simulating different vehicle configurations, allowing for a quick estimation of CO2 emissions and energy consumption from heavy duty vehicles of different characteristics. VECTO simulates CO2 emissions and fuel consumption based on vehicle longitudinal dynamics using a driver model for simulation of target speed cycles. The required load to be delivered by the internal combustion engine is calculated in 1Hz based on the driving resistances, the power losses in the drivetrain system and the power consumption of the vehicle auxiliary units. Engine speed is determined based on a gear shift model, the gear ratios and the wheel diameter. Fuel consumption and CO2 emissions are then interpolated from an engine fuel/CO2 map. The VECTO software is written in C#.

model inputs

Main inputs

  • Engine fuel consumption map
  • Torque loss maps at the drive train
  • Vehicle mass
  • Vehicle road loads
  • Vehicle characteristics
  • Vehicle auxiliary systems

 

model outputs

The list of output values has been defined together by the developers and industry.  The model provides CO2 and fuel consumption results over official and user defined driving cycles (mission profiles). Various metrics can be calculated such as gCO2/km, gCO2/t-km, gCO2/passenger-km litres/100km, l/100passenger-km etc.

Intended field of application

policy role

This model is the tool of reference for the certification of CO2 from heavy-duty vehicles. After further development it will also allow the Commission to assess the effects of new technologies. The results of this model can be used in order to estimate the effects of new technologies on the CO2 emissions and fuel consumption of heavy-duty vehicles.

VECTO has been used in impact assessment studies done by DG CLIMA on CO2 monitoring and standards.

The following kind of questions can be answered, related to Impact Subcategory Vehicle Emissions, Fuel and Energy Consumption :

  • What is the impact of certain vehicle specifics on the fuel consumption and CO2 emissions of Heavy Duty Vehicles?
  • Can a given technology option reduce energy/fuel consumption of Heavy Duty Vehicles by Z%? Does it increase or decrease vehicle emissions? Will the option increase/decrease energy and fuel needs/consumption?
  • What is the likely performance of today's Heavy Duty Vehicle fleet with respect to energy consumption?
policy areas
  • Climate action 
  • Energy 
  • Transport 
  • Research and innovation 

Model transparency and quality assurance

Are uncertainties accounted for in your simulations?
YES - The uncertainties have been quantified by several stakeholders including heavy duty vehicle manufacturers.
Has the model undergone sensitivity analysis?
YES - Yes the JRC has made a first sensitivity analysis, the findings are currently under publication.
Has the model been published in peer review articles?
YES - It undergoes continuous review by industrial stakeholders who use it for certification purposes and independently by the JRC.
Has the model formally undergone scientific review by a panel of international experts?
NO
Has model validation been done? Have model predictions been confronted with observed data (ex-post)?
YES - Three reports have been published to date on the topic by the JRC. Validation has been done by some member states and by industrial stakeholders.
To what extent do input data come from publicly available sources?
Based on both publicly available and restricted-access sources
Is the full model database as such available to external users?
NO - There is no underlying database, the input is vehicle specific and derived during the certification process.
Have model results been presented in publicly available reports?
YES
Have output datasets been made publicly available?
NO - Depends on who is using the model. As JRC we draft reports and papers on the simulations we run with VECTO.
Is there any user friendly interface presenting model results that is accessible to the public?
NO
Has the model been documented in a publicly available dedicated report or a manual?
YES

Intellectual property rights

Licence type
Free Software licence

application to the impact assessment

Please note that in the annex 4 of the impact assessment report, the general description of the model (available in MIDAS) has to be complemented with the specific information on how the model has been applied in the impact assessment.

See Better Regulation Toolbox, tool #11 Format of the impact assessment report).