Until now, this has been done manually, with the coupling and uncoupling of tractors and trailers representing an everyday event in logistics operations. “Anyone seriously considering autonomous driving for commercial vehicles should also be thinking about automating the coupling and uncoupling processes,” points out Alan Feltham, who works at SAF-HOLLAND on the development of coupling systems in Europe, the Middle East and Africa (the EMEA region). This issue is what prompted a global team of SAF-HOLLAND engineers to launch the “Automatic Coupling System” project in April 2017. The first prototype of the system was presented at the 2018 IAA Commercial Vehicles trade show.
Coupling a trailer to the tractor is still a manual process that has a certain number of possible errors built in and takes a skilled driver about five minutes to complete. The driver first sets the tractor back with the fifth wheel open until the coupling under the trailer is slightly ahead of the kingpin. Then the rear axle of the tractor is raised with the help of air springs to allow the coupling plate to rest directly on the trailer’s skid plate. The fifth wheel must be in direct contact with the skid plate, otherwise there is a risk of so-called “high coupling,” where the kingpin does not enter and lock into the fifth wheel lock but rather on the coupling plate or the lock. Another possible error can occur during the manual connection of the electrical and pneumatic supply lines. To avoid this, the driver climbs into the space between the cab and trailer and puts the connections together by hand. EBS and pneumatic control lines are particularly crucial for the semitrailer’s braking system. Any faults can lead to a failure in the brake’s function.