Written By: Rebecca Morris
Volvo recently wrapped up with their Safe Road Trains for the Environment (SARTE) project, which provided a realistic look at what autonomous driving could look like using today’s technology. The program, which tested the implementation of road trains — or “platoons,” as Volvo called them — on conventional highways. The program was created in hopes of allowing drivers to experience the best of both worlds when it comes to multi-tasking and using public transportation – all from the comfort of your own vehicle.
As the only participating car manufacturer in SARTE, Volvo used a manually driven semi-truck to lead the pack, which was followed by another truck and three Volvo passenger vehicles. These passenger vehicles included two S60 cars and an XC60 sport utility vehicle. The test demonstrated that a lead vehicle, with an experienced driver who is thoroughly familiar with the route behind the wheel, can allow others in tow to mimic the lead vehicle’s movements through the use of electronic driving aides. The idea also allows others to join the road train at any point during the route, at which time the autonomous vehicle control systems would take over, allowing the driver to relax as a passenger.
Volvo was able to achieve the feat by using several different technologies, some are already present in production vehicles. According to Volvo Technical Specialist Erik Coelingh, the company expanded the capabilities of its camera, radar, and laser technology systems currently used in present safety systems like Adaptive Cruise Control, City Safety, Lane Keeping Aid, Blind Spot Information System, and Park Assist Pilot. These systems were made to work in conjunction with other new features added specifically for the test. These included a prototype human-machine interface that included a touch screen for displaying vital information and carrying out requests, like joining and leaving the road train, as well as a vehicle-to-vehicle system that lets vehicles within the train communicate with one another.
During the test, all vehicles behind the lead truck were driven autonomously at speeds up to 55 mph. At times, vehicles in the train maintained a distance of only four meters, or just more than 13 feet, apart. Why so close? Vehicles driving in close proximity with one another are able to create a slip-stream affect (think drafting) to achieve a lower drag coefficient. Combined with reduced speed variations normally associated with driving in traffic, this can increase fuel efficiency by 10-20%.
The company’s long-term vision is to create a transportation system using their road train method in a way that is more attractive and comfortable than leaving your personal vehicle behind to use public transportation. To do so, the company hopes to integrate the ability to book, join, and leave the road trains by using Volvo’s Sensus Infotainment system. While Volvo insists the technology is production-ready, the system must first become more cost effective.
But even so, don’t expect to see autonomous vehicle trains on a road near you anytime soon. Volvo’s Coelingh says that there are several issues to solve on Europe’s roads first before road trains become a reality. However, the test did include a major study to identify what infrastructural changes are necessary in Europe to begin using the system in daily life.