A group of Scania experts in different fields have teamed up and developed a concept truck, which, even without the cab, has the company’s modular system at the heart of the design.

As different industries look to streamline transport assignments and make them more sustainable, self-driving vehicles are increasingly being considered. Mines and large closed construction sites are examples of environments that are favourable for self-driving pilots since they are well-controlled locations.

“With the Scania AXL concept truck, we are taking a significant step towards the smart transport systems of the future, where self-driving vehicles will play a natural part,” says Scania’s President and CEO Henrik Henriksson. “We continue to build and pilot concepts to demonstrate what we can do with the technology that is available today.”

For autonomous vehicles, software is in many ways more important than hardware. Scania AXL is steered and monitored by an intelligent control environment. In mines, for example, the autonomous operations are facilitated by a logistics system that tells the vehicle how it should perform.

“We already have self-driving trucks in customer operations. However so far, they have been with room for a safety driver who can intervene if necessary. Scania AXL does not have a cab and that changes the game significantly,” says Claes Erixon, Head of Research and Development at Scania. “The development in self-driving vehicles has made great strides in the past years. We still don’t have all the answers, but through concept vehicles like Scania AXL we break new ground and continue to learn at great speed.”

The combustion engine that powers the concept vehicle is an example of how traditional and new technology is mixed. It is advantageously powered by renewable biofuel.

The robust and powerful features and design behind Scania AXL match the tougher environments in mines and large construction sites. A new intelligent front module replaces the traditional cab, but even without a cab the concept is easily recognisable as a Scania.

In many respects, the engineers entrusted with developing the concept truck Scania AXL entered uncharted territory. For most, building the autonomous truck has been the greatest challenge of their professional lives.

In a very short time, Scania’s engineers have transformed a conventional truck to a fully autonomous vehicle, with the traditional cab replaced by a front module with intelligent technology.

“We’ve learned a lot and I believe there now is the widespread insight that it is much harder than many initially realised to develop a safe self-driving vehicle for varying applications in different environments,” says Eric Falkgrim, Project Manager for Scania AXL.

Scania AXL’s brain is the intelligent front module, where data from cameras, radar and lidar sensors together generate a common view of the vehicle’s immediate surroundings.

Development Engineer Magnus Granström was one of those developing the software for the front module. “In software terms, the greatest challenge has been to ensure that the concept truck is sufficiently safe to be driven without a steering wheel. In essence, the steering wheel has been the precaution through which a driver can intervene if something goes wrong. When we don’t have that, the system must simply work perfectly,” he says.

Development Engineer Carl Wettergren has been involved throughout the Scania AXL project. “One of the early issues was to what extent the front module could be subjected to motion. The aim was for the cameras and sensors to be built into the module and we had lengthy discussions how these would connect with the chassis.”

Senior Mechanic Pierre Jacobsson says that during its development, Scania AXL was sometimes hoisted into axle stands to prevent the truck from moving uncontrolled. He’s delighted with the end product.

“Two years ago, we saw some rough sketches of what the truck might look like and it seemed very strange. This was something completely new for us. But the result is far cooler than that. It’s bold, really bold.”

A key motivation for Scania’s development of the self-driving truck has been to start exploring customer needs.

“When autonomous vehicles have reached full maturity and we approach customers, we need to understand all their needs,” says Falkgrim. “This is our interpretation of what we believe customers may require for future transport needs. And we welcome their response.”

“It was a tremendous feeling to see the project cross the finishing line, when Scania AXL actually drove for the first time. That was a truly amazing experience,” Falkgrim recalls.

With cameras, radar and lidar sensors, Scania’s engineers have taken powerful steps towards fully autonomous vehicles. The challenge has been to replace the human eye and the ability of the human brain to process decisions based on what the eye sees.

Autonomous vehicles have often relied on data from cameras and radar. Radar sensors are reliable, but the resolution is insufficient to identify the likes of pedestrians and small objects at a distance. The camera offers a sufficient level of detail and a good overview in two dimensions but requires massive software to convert 2D images of the surrounding environment to 3D. Generally, for autonomous vehicles, software is more important than hardware.

For safe autonomous driving, an additional sensor is therefore needed. It’s called lidar, which stands for light detection and ranging. “We need there to be overlap between the sensors, so that one can be a backup to take over from the other if needs be,” says Fredrich Claezon, System Architect for Autonomous Vehicles. “What happens if the camera and radar suggest conflicting information? Which of these sensors should we trust? With lidar, we can obtain a better basis for decisions.”

Scania’s first fully autonomous self-driving concept truck, Scania AXL, is equipped with cameras, radar, lidar and GPS receivers. The system is designed for a level that meets the operational needs of mines. “The system isn’t yet street smart but it’s certainly smart enough for being used in mines,” says Development Engineer Magnus Granström, Autonomous Systems Development.

The human eye is not easily replaced but a relatively good overview of surroundings can be obtained through sensors. “In this case, we see what we need to see,” Granström explains. “Driving in a mine is fairly simple and predictable. If you’re driving in a more dynamic and less predictable environment, more work is needed.”

It’s been difficult to decide just how complex the system should be. This involves balancing an opportunity to develop a more general system for many applications with ensuring there is a robust and reliable system for the mining industry. “Scania AXL would most probably not be fit for city driving but considering the envisioned environment and planned assignments, it’s sufficiently smart,” says Granström.

A vehicle from Scania must be recognised as a Scania even if it comes without the cab. The fully autonomous Scania AXL concept is tailored for heavy duty operations and should therefore convey robustness and strength.

Scania’s new autonomous truck concept is another major step forward in the development of future vehicles. “Since this is a new concept, there are plenty of things that we could do in terms of how it might look, but it is imperative to show everyone that this is still a Scania,” says Xavi Carreras Castro, the designer at Scania’s vehicle styling department with responsibility for Scania AXL.

Extra reading: Robustness and power

Vehicle styling is mainly determined by the planned environment and application. If the vehicle is being designed for mining and construction work, it should convey robustness and power, whereas the design of a self-driving distribution truck for downtown cities should give a gentler, kinder impression.

“This is the first time that that we’ve built a truck that has many new components and technologies. That enables us to alter earlier forms and expressions. This is what we believe the future looks like, so this has been really exciting.”

The challenge has been to balance the truck’s proportions and blend the front module with the tipper unit. “Half the cab is gone without a driver. A conventional mining truck has two distinct parts – the cab and the tipper unit. We’ve aimed for an integrated styling with a more dynamic design language.”

Although the Scania AXL concept is a novel and innovative vehicle it can be clearly recognised as a Scania. The colours identify it as part of the Scania family and there is still room for the characteristic ‘wrapping T’, which on conventional trucks is formed by the grille and the windscreen.

The development and design of the concept truck has required many new approaches, since little was known when the project started. “It will be a tremendous feeling when a truck such as this eventually appears at a mine,” says Carreras Castro.

You can find out more about the Scania AXL here.