Within the Automated Driving Programme TNO is working on the accelerated implementation of automated driving for both passenger cars and trucks with the underlying goal of boosting traffic safety and traffic flow as well as reducing fuel consumption and emissions. Automated and cooperative driving is a key component of this programme.
Together with industry and the government, TNO is working on the technology that is intended to actually make automated driving possible on public roads, for both passenger cars and trucks. Cooperative and affordable. Safe and reliable.
Cooperative Adaptive Cruise Control
You can reduce the number of vehicle hours lost through traffic jams and cut fuel consumption and emissions by a) allowing vehicles to drive closer behind each other and b) suppressing speed variations and thereby creating a stable traffic picture, without the incidence of shockwave traffic jams. This can only be effected by automating acceleration and braking through the use of sensors in the vehicle, such as radar and camera, and through the use of wireless communication, which enables the vehicles to communicate and cooperate with each other. Wireless communication generates much more information about other road users than using conventional sensors like radar and camera, and it’s also much faster. The result is a stable traffic flow with a 0.3 s headway (time required to bridge the distance to the vehicle in front) in contrast to the unstable (human) behaviour that we now see on the roads, with a headway of more than 1s. Cooperative Adaptive Cruise Control (CACC) is the term given to this kind of cooperative automation; a much improved version of the commercially available Adaptive Cruise Control.
CACC in trucks
The use of CACC in trucks has a significant additional benefit in that fuel consumption can be reduced by around 10% as a result of platooning, although automated steering is necessary. This is because with trucks having a short headway of 0.3 s between each other, the driver of the truck behind quite literally is unable to see the traffic situation and therefore cannot be expected to steer the vehicle himself. The result, then, is a fully automated truck whose behaviour is aligned to the truck in front through vehicle-to-vehicle communication.
TNO expects the first Truck Platooning trucks to be driving on Dutch motorways and major provincial highways by 2020. These will be two virtually coupled trucks whereby one driver actually drives and the other has no driving task to fulfil. The initial phase was completed on 25 March 2015, during the opening day of Automotive Week, with a demonstration of 2-truck platooning on the A270 in Helmond. TNO and DAF successfully showed the technical feasibility of automated platooning with two trucks.
Automatic influence on road traffic
Automating road transport, as described above, opens up the possibility to automatically influence traffic through infrastructure – vehicle communication. For example, the motorway infrastructure could transmit a (varying) maximum speed and (equally varying) minimum headway in anticipation of a traffic jam or to create space for vehicles to merging from the slip road. The vehicles will then automatically adjust the maximum speed and headway, informing the occupants of the reason for doing so via a pictogram on the onboard computer screen.