|SARTRE public road test. Click to enlarge.
Vehicle platoon tests in the SARTRE (Safe Road Trains for the Environment) project—a joint venture between Ricardo UK Ltd, Applus+ Idiada, Tecnalia Research & Innovation, Institut für Kraftfahrzeuge Aachen (IKA), SP Technical Research Institute, Volvo Technology and Volvo Car Corporation—are making progress. (Earlier post.)
For the first time a road train comprising a Volvo XC60, a Volvo V60 and a Volvo S60 plus one truck automatically driving in convoy behind a lead vehicle has operated on a public motorway among other road users.
While there remain many challenges to full scale implementation, the SARTRE project has demonstrated a very practical approach to the implementation of safe road train technology that is capable of delivering an improved driving experience, better road space utilization and reduced carbon dioxide emissions.
Once the fuel consumption measurements are completed we will be drawing on the learning we have gained developing the platoon system and understanding the various human factors, to assess the likely roadmap and mechanisms for platoons and platoon technology to be operational on public highways—at which point we believe there will be a really positive impact on highway utilization.—SARTRE project director, Tom Robinson of Ricardo
A road train consists of a lead vehicle driven by a professional driver followed by a number of vehicles. Building on already existing safety systems—including features such as cameras, radar and laser sensors—the vehicles 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. The project also aims to improve traffic safety, reduce environmental impact and cut the risk of traffic tailbacks.
The vehicles drove at 85 km/h (53 mph). The gap between each vehicle was only six meters; during trials on the test circuit, the researchers tried out gaps from five to fifteen meters.
The three-year SARTRE project has been under way since 2009. All told, the vehicles in the project have covered about 10,000 kilometers (6,214 miles). 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. The estimated fuel consumption saving for high speed highway operation of road trains is in the region of 20% depending on vehicle spacing and geometry.
We covered 200 kilometeres in one day and the test turned out well. We’re really delighted. Driving among other road-users is a great milestone in our project. It was truly thrilling.
We’ve learnt a whole lot during this period. People think that autonomous driving is science fiction, but the fact is that the technology is already here. From the purely conceptual viewpoint, it works fine and road train will be around in one form or another in the future.
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.—Linda Wahlström, project manager for the SARTRE project at Volvo Car Corporation
Part-funded by the European Commission under the Framework 7 programme, SARTRE is led by Ricardo UK Ltd. SARTRE aims to encourage a step change in personal transport usage through the development of safe environmental road trains (platoons). The objectives of SARTRE may be summarized as:
To 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.
To enhance, develop and integrate technologies for a prototype platooning system such that the defined strategies can be assessed under real world scenarios.
To demonstrate how the use of platoons can lead to environmental, safety and congestion improvements.
To illustrate how a new business model can be used to encourage the use of platoons with benefits to both lead vehicle operators and to platoon subscribers.