In case you have never heard of it, a road train is a convoy of vehicles following in relative close quarters. The SARTRE road train takes this to another level with laser sensors, cameras and radar technology working in tandem to make this convoy travel autonomously. SARTRE stands for ‘Safe Road Trains for the Environment’ and as the name suggests plans to develop fully autonomous road train technology into a reality.
The project is a joint venture between Ricardo UK Ltd, Applus+ Idiada (Spain), Tecnalia Research & Innovation (Spain), Institut fürKraftfahrzeuge Aachen (IKA) from Germany, SP Technical Research Institute, Volvo Technology and Volvo Car Corporation of Sweden (also part funded by the European Commission). Recently, a vehicle platoon test showed significant progress after a first ever road train among other road users on a motorway outside Barcelona succeeded in proving its concept. The convoy comprised of a Volvo XC60, a Volvo V60 and a Volvo S60 plus one truck automatically driving behind a lead vehicle at 85kmh. Gaps between each vehicle was just 6 metres. “We covered 200 kilometres in one day and the test turned out well. We’re really delighted,” says Linda Wahlström, project manager for the SARTRE project at Volvo Car Corporation.
The lead vehicle was driven by a professional driver followed by the other vehicles. Building on Volvo Car Corporation’s and Volvo Technology’s already existing safety, all cars in the convoy monitor the lead vehicle and also other vehicles in their immediate vicinity. By adding in wireless communication, the vehicles in the platoon “mimic” the lead vehicle using Ricardo autonomous control; accelerating, braking and turning in exactly the same way as the leader.
The project aims to deliver improved comfort for drivers, who can now spend their time doing other things while driving. They can work on their laptops, read a book or sit back and enjoy a relaxed lunch. Naturally the project also aims to improve traffic safety, reduce environmental impact and – thanks to smooth speed control – cut the risk of traffic tailbacks.
Linda Wahlström adds, “We’ve focused really hard on changing as little as possible in existing systems. Everything should function without any infrastructure changes to the roads or expensive additional components in the cars. Apart from the software developed as part of the project, it is really only the wireless network installed between the cars that set them apart from other cars available in showrooms today.”
The three-year SARTRE project has been under way since 2009. All told, the vehicles in the project have covered about 10,000km. After the test on the public roads in Spain, the project is now entering a new phase with the focus on analysis of fuel consumption.
If successful, the benefits from SARTRE are expected to be significant. The estimated fuel consumption saving for high speed highway operation of road trains is in the region of 20 percentdepending on vehicle spacing and geometry. Safety benefits will arise from the reduction of accidents caused by driver action and driver fatigue. The utilization of existing road capacity will also be increased with a potential consequential reduction in journey times.