Sartre - Safe Road Trains for the Environment Reducing Fuel Consumption through Lower Aerodynamic Drag Coefficient 2011-36-0060

The SARTRE Project is an FP7 European collaborative project funded by the EC with the participation of 7 entities from 4 countries. The SARTRE project focuses on the design, set up, evaluation and validation of road train systems that do not require modification to the actual road infrastructure, making use of available technologies for in-vehicle applied systems.

The SARTRE project will define a set of acceptable platooning strategies that will allow road trains to operate on public highways without changes to the road and roadside infrastructure therefore enhancing, developing and integrating technologies for a prototype platooning system such that the defined strategies can be assessed under real world scenarios. Also, the project will show how the use of platoons can lead to environmental, safety and congestion improvements.

The project bases the functionality of the platooning system in safety improvements from autonomous control systems to be used in lead vehicles (trucks) and following vehicles (trucks, cars, SUVs). Considering that 87% of road fatalities include contribution from the drivers, automated systems prove to be safer means while striving for more efficient personal transportation.

Smaller time and space gaps between vehicles with the aid of autonomous control will contribute by improving the traffic congestion, to provide the maximum efficiency. This will translate into a delay in the traffic collapse and reduced traffic dynamics on highways. This will also become an important aspect of the project, as a significant fuel efficiency improvement achieved from a reduction in the aerodynamic drag coefficient of the entire platoon is expected. An average 20% decrease has been found for 4 vehicles with a 0.2 vehicle length gap in previous projects.

SARTRE will initially perform a simulation of the most representative platoon configurations to obtain the expected drag coefficient reduction, in order to then calculate the expected fuel consumption savings. Having this data in hand, a real fuel consumption evaluation will be performed while in the validation trials, to make an exact correlation of the calculated data and the real life data. This is a challenge that has been addressed in order to develop new capabilities that can optimize future aerodynamic calculations and reduce the cost of testing for specific make and models and platoon combinations.

The challenge addressed by the simulation relies on the length of the platoon, the requirement to keep the wake effect flowing toward the end of the platoon and the different platoon configurations to be analyzed, having very different vehicle geometries and gaps in the mix. Up to date, the only simulations and tests available were carried out using platoons with identical vehicles and vehicle gaps.