Challenge raises as many issues as solutions to truck platooning

If carmakers dream of producing vehicles that are fully autonomous robots, the manufacturers of trucks entertain somewhat more modest visions. They foresee platoons of goods-laden lorries, equipped with state-of-the-art connectivity and safety systems, travelling down the highway in perfect alignment, separated by precise distances, braking or accelerating in full synchronisation and, at least for now, with drivers at the wheel.

Truck platooning has many advantages, both commercial and societal, including increased road safety, improved traffic flow, less fuel consumption, lower CO2 emissions and lower shipping costs. So, in Europe, governments, truck makers, shippers and transporters have begun collaborating to make it happen.

The first practical step in bringing platooning to European roads was taken in early April, road authorities and truck-OEMs, on the initiative of the Dutch EU presidency, carried out the world’s first transcontinental on-road platooning trial, the EU Truck Platooning Challenge 2016. The event involved platoons of two or three trucks from six truck-OEMs – DAF, Daimler, Iveco, MAN, Scania and Volvo – which followed pre-determined motorway corridors from their home base or production location to the APM Terminals in the Port of Rotterdam. The trucks originating in Sweden, Scanias and Volvos, covered the greatest distance, more than 2,000km (1,245 miles), and crossed the most borders, four.

According to Anders Kellström, senior planning manager, business and technology, at Volvo Group Trucks Technology, and the company’s internal project manager for the challenge, the purpose of the event was “to exercise cross-border cooperation because… it has to work in all countries and it is essential that road authorities, truck manufacturers and legislators all work together to make this infrastructure, this system, work”.

The challenge revealed, first of all, that there was a great deal of pan-European administrative work to be done. “We learned that legislation is very different in the different countries, so it’s pretty complicated to get permission in a harmonised way for trucks to drive close to each other on a nation’s roads,” Kellström said. “We also learned that different stakeholders have different perspectives on what a safe distance between trucks should be. That is not a given.”

Some countries, he explained, measure defined safe distances between trucks in terms of time while others use metres. And, perhaps most vexing, different road authorities proscribed different distances for the same technology, anywhere from 0.5 seconds up to 1.3 seconds apart.

According to Dirk-Jan de Bruijn, programme director of the challenge, the solution to this problem goes beyond just harmonising regulations. “It’s also a matter of traffic,” he explained. “For example, the highway traffic flow in the Netherlands is quite different from that in Sweden. So we might require different distances between the trucks in Sweden than in the Netherlands, based on the traffic density. We need to have more real-life trials to have enough data” to establish standard truck distances in platoons.

This calculation is not merely based on speed and braking but also on interacting with the ambient traffic. For example, if the distance between trucks is large enough, other cars could interpose themselves, disrupting the platoon. “Right now, we have been testing the trucks being about 0.5 seconds apart, which is about 8 to 10 metres, and not large enough to permit other cars to join the platoon,” de Bruijn said. “But is that an appropriate distance in all traffic conditions? We will have to find out in real traffic.”

The platoons in the challenge were composed of identical trucks from the same truck maker. But mono-brand truck platoons will probably be rare in the future. “If a Volvo truck can platoon only with another Volvo truck, it limits the number of times a customer actually can platoon,” Kellström said. “So the whole market becomes less attractive for platooning. We realised that mixed platooning is a prerequisite for making the whole idea of platooning more attractive to customers, because then the utilisation of platooning goes up a lot.”

Kellströmwants platooning to be a common occurrence on the road, “a part of daily life,” as he put it. “Once a truck goes on the road, it should be able to platoon with other trucks of any brand. That’s what we see in the future.”

He envisages mixed-brand platoons that individual trucks can join and leave on the fly. This raises a number of technological issues, none more important than how to configure the platoon given the different loads and horsepower of the trucks, which becomes critical when the platoon climbs or descends steep slopes.

For example, if the lead truck is more powerful and/or carries a smaller load than some of those that follow, “a consequence might be that the platoon breaks up,” Kellström said. Volvo is currently carrying out pilot projects in the US trying to solve this issue. The trials are experimenting with systems that would use data from a truck wanting to join a platoon to calculate its optimal spot in the column after combining it with the data of trucks already in the platoon.

“There are so many parameters to consider,” he explained. “You have aerodynamics, you have braking performance, weight, horsepower. How to actually organise the platoon in road conditions still requires more development, more data, more learning.”

De Bruijn believes that commercial truck platooning will be launched in five to eight years. The next on-road testing will involve platoons of mixed brands in several countries. This trial will start in 2017 and will take two to three years to complete. He said the most important goal of these trials will be to develop a connectivity standard, so that trucks from every brand on the road will be able to communicate with each other. “Right now, we have nothing of the kind.”

Leave a comment

Your email address will not be published. Required fields are marked *