10,000 hours of endurance testing
HAMM has already successfully completed the first steps of the journey. Not just on paper but in practice, in the form of endurance testing at the Tirschenreuth plant, and by developing a driverless "shadowing roller" that follows a preceding machine. The endurance test track has been operational since 2014, with the primary purpose of testing prototypes. Since then, the developers at HAMM have been testing their new developments under reproducible conditions and in around-the-clock operation for weeks at a time – with no driver at the wheel. In these trials, the machines autonomously complete a specified program, drive themselves to refueling points and park themselves when the test is completed. To prevent collisions with persons or objects, the developers at HAMM have outfitted the rollers with comprehensive surroundings-monitoring systems. "We have now clocked up over 10,000 hours on this test track and learned a great deal about autonomous driving in the process," explains Dipl.-Ing. Hans-Peter Patzner, who worked on the development of the control system for the project. Patzner is now looking ahead to the next challenge, because the current construction of a second test track at HAMM will enable two different rollers to drive simultaneously. "For this, we have designed a collision monitoring system, which represents another important step toward autonomous driving," says the automation specialist.
Driverless shadowing roller
The second project had a different focus: In collaboration with the University of Osnabrück, the team has successfully converted a roller that, without a driver, automatically follows a simulated road paver. According to Head of Development, Dr.-Ing. Römer, "If you further consider the approach of this 'shadowing roller', we can leverage much potential through the automation of the compaction process. There will be an increase in quality thanks to compliance with lanes and windows of speed. Targeted braking of the roller can avoid going beyond the rolling areas and any subsequent over-compaction. Not least, the extremely precise change of compaction lanes helps to prevent deformation. Together, these systems automatically lead to greater efficiency, in particular when such concepts are applied across the fleet."
Automation for more quality
No matter how autonomous compaction is to be designed – from our present point of view, the way there involves assistance systems. "They will relieve the burden on drivers in the coming years bit by bit, but are already inspired by the vision of the autonomous roller. And, of course, every new assistance function – independently of the vision of autonomous rollers – is beneficial for the compaction process," explains Dr. Klumpp. As long as surroundings monitoring is not sufficiently precise for fully autonomous driving, a roller driver will have to be in the cabin. He would only take over in specific situations, for example for refueling, during loading and unloading, or in the event of unforeseen incidents. A similar situation already prevails in the field of aviation: In modern commercial aircraft, the autopilot and other systems carry out the greater part of in-flight tasks. The pilots only control the aircraft during take-off and landing, and in exceptional situations, otherwise their main task is to monitor the processes.