Truck platooning system allows a convoy of commercial vehicles to operate with only one human driver
In what it describes as a “step forward on the road to the fully connected and autonomous commercial vehicle”, Mercedes Benz parent company Daimler has for the first time demonstrated its system for operating a convoy of vehicles working in a coordinated task with only one of the vehicles controlled by a human driver, with four vehicles working together to simulate clearing snow from an airfield. Known as truck platooning, this technology has potential for increasing productivity on normal roads and in enclosed facilities.
The demonstration involved four Arco tractor units equipped with Daimler’s new Remote Truck Interface (RTI), which coordinates data exchange between the vehicles and operates three of them remotely. All the vehicles use dual GPS tracking and vehicle-to-vehicle (V2V) communication, which exchanges a full telematics data set every 0.1 seconds.
Every vehicle equipped with the RTI can act as the lead or a follower in the platoon; the driver just needs to designate the lead and define the number and sequence of follower vehicles on a control pad on the dashboard. The convoy can include up to 14 units.
“This opens up new possibilities for our customers: High-precision manoeuvring procedures of conventional trucks, remotely controlled by the driver outside the cab – for example, positioned at the rear of the vehicle with a perfect view of the manoeuvres – are possible, as is unmanned driving in mines, at container terminals or other closed-off sites”, said Martin Zeilinger, Head of Advanced Engineering at Daimler Trucks.
The RTI connects the truck with the outside world, while other functions — such as track computer, wireless data exchange and the operating panel — are housed separately. The platoon driver can control the subordinate vehicles to start and stop their engines; apply the handbrake; steer; operate the throttle; brake; change gear; activate and deactivate differential locks; use signals and safety beacons; and operate peripheral machinery attached to the tractor unit, such as the snow blower.
“An important component of the RTI control unit is the integrated safety concept. This means that all vehicle functions are monitored. The safety routine is executed as soon as an error occurs. In this way we can ensure that the vehicles can be stopped safely and quickly if needed, and can then simply be operated manually”, Zeilinger explained.
The demonstration of clearing snow from an airfield is an example of a situation where platooning would have important real-world applications, Daimler said. Heavy snowfall is difficult to predict a long time ahead, and therefore airports must ensure that a fleet of snow-clearance vehicles and all their necessary drivers are on standby all through the winter, in case they are needed — when most of the time they won’t be, tying up resources. Operating the vehicles as a semi-autonomous platoon means that only one driver needs to be available, who can then clear the affected area “with pinpoint precision.”
Snow clearance is an exacting operation. For an airport the size of Frankfurt, settling snow has to be cleared to a width of 60m in a single pass by a coordinated convoy of 14 vehicles in an overlapping formation, which pass snow from one vehicle down to the next. The formation must be maintained in weather conditions with frequently low visibility, day and night, with snow constantly being thrown up by the vehicle in front. The GPS allows the vehicles to be positioned to 3cm precision, with the driver operating the first vehicle which has the best visibility.
The test was carried out on the former Pferdsfeld airbase near Stuttgart, with four tractors, each equipped with a two-tonne snowplough blade and with the last unit towing an independently-powered sweeper-blower unit semitrailer. This last vehicle combination, which removes the last traces of snow from the ground, is 23m long and weighs 25 tonnes.