Volvo Buses has developed an advanced support system with high precision. When braking to a stop and starting from it, the bus runs autonomously, which means that the driver’s role will then be to monitor the situation.

– They go in when required, if there is a situation that needs to be averted or if they need to stop the bus. But otherwise it navigates and manages the lateral position itself, with acceleration and braking, says Joakim Jonsson, project manager for research projects in self-driving buses at Volvo Buses to Ny Teknik.

Chalmers has now conducted a user study where ten bus drivers have tested the system. Joakim says that before the study they were unsure of how the drivers would receive the solution, and if they would be offended by the system then the technology can be interpreted as not trusting their professional knowledge. But no driver made such a comment in the evaluation – on the contrary, everyone received the system very positively. And autonomy can help with more than just stops.

– We also have so that we can maneuver a roundabout in what we call “harsh curving”, when you get a lateral displacement of the passengers, that they slide to the side. It can be any 90-degree curve that is a little incorrectly dosed or heavily dosed – then you can also transfer the bus in autonomous mode and it takes care of speed and steering itself. Then the driver takes over and drives manually again. We see potential with the system, he says.

Maintains concentration longer with driver support systems

The technology can mean that new bus drivers get into traffic faster, but above all it is about unloading. Everyone is able to drive for 45 minutes, but towards the end of the work shift it is another five.

– You lose concentration at the end of the work shift, but if you have a driver support system, you can keep the focus longer. We did not have such long tests in the study, but it is a theory that is consistent with what the drivers said – that with a large number of runs to the stop per work shift, the system would help incredibly much, both mentally and physically in that you can relax in a different way, says Joakim.

The system is intended for low speeds, from 20 km / h and down to 0 – although it is theoretically possible to activate at up to 50 km / h. The surroundings around the bus are taken in via GPS, radar, camera and lidar sensor, but according to Joakim, the lidar is still far too expensive.

– It is a very good sensor that provides a very good quality of navigation compared to the other three. If you drive among high-rise buildings or under a roof or viaduct, the GPS can start operating. There is quite a lot of noise on the radar, the camera can not measure distance in the same way. With lidar, the disadvantage is, among other things, that it cannot see colors, even if it is not needed for a system like this, he says.

The question then is how the system will be able to handle a metropolitan traffic where very little consideration is given, for example to a swinging bus preference.

– It is the most difficult scenario to drive self-driving in, mixed traffic as we call it, where you have to take into account and handle all traffic situations that may arise. And no one is there now, and it will be a very long time before someone is there – that you can drive like a human being that way, he says.

Challenge as long as there is “mixed traffic”

Self-driving systems run with much larger margins, while we humans have much more chances and ignore the Swedish Transport Agency’s recommendations on distance, speed, braking readiness and current traffic rules.

– But an autonomous vehicle will not deal with traffic. As long as there is mixed traffic, we have a big challenge, says Joakim Jonsson.

He says that Volvo Buses gets a lot of questions about the system, because many are interested in this type of solution and there is a great need for the technology. But at present, Volvo Buses cannot provide a time when the system may be available on the market.