To do this, Iwai and his colleagues developed – or modified – a suite of technologies including an automated steering system, automatic vehicle-following system and cooperative adaptive cruise control.
In the trials, the lead vehicle – driven by a specially trained driver – took control of the caravan and led it round and round the test track issuing commands on the fly. For example, the speed of the leader was communicated wirelessly every 20 milliseconds to allow the train to make constant adjustments and to ensure that they were driving at both an optimum and safe distance.
But the second, third, and fourth vehicles are not dumb either – they were also equipped with millimeter-wave radar and infrared laser radars to detect obstacles and recognize lane markings, as well as a series of algorithms and fail-safe controls to better manage the vehicles.
Although the set-up sounds complex, Iwai believes that it would be a relatively simple task to upgrade modern trucks, many of which are already fitted with most elements of the technology. “We think that the eventual system/product would be sufficiently affordable for truck owners.”
Crucially, the demo also showed that the trucks’ fuel economy improved by 15% or more on average, by allowing the vehicles to slip stream each other like drafting Tour de France riders. It also showed that the lead truck can benefit from less drag at its rear as the ‘bow-wave’ of the tailing vehicle in-effect “pushes” the lead truck forward.
The tests were the first of a series for the organization. “Our next step is to obtain a permit and test this technology on public roads,” says Iwai. “In order to ensure safety and reliability of the system, we need to conduct many field demonstrations. In addition, we think it will be necessary to establish international technical standards.”
In fact many questions remain before the system rolls out into common use. The biggest one of these is whether the public are ready for semi-autonomous vehicles to trundle alongside them. And then there is the question of whether truck drivers will put their faith in the technology.
At the same time several technical wrinkles need to be ironed out, such as automating the process of lane changing, or figuring out how drivers will merge with and leave the platoon. Ensuring that long road trains do not present a barrier to vehicles entering or exiting traffic flows will also have to be addressed.
Trials like the one in Japan also raise less obvious questions, such as how windscreens will deal with being pelted by grit and stones kicked up between vehicles or how the view-obscuring spray of rain water from long trains will affect other road users.
And if convoys go co-ed and mix cars and trucks, there are new road rules to think about, such as whether trucks only go at the front to accommodate to their longer stopping distance and therefore how new trucks insert themselves into the train.
But engineers and planners working on the technology believe none of these issues are insurmountable and that road trains could be cruising highways sometime in the next decade. Perhaps in the not-too-distant future, you yourself will commute to work on a robotic conga line, along with a line up of other drivers not paying attention to driving.