Unique for buses and coaches: the new Active Drive Assist 2 represents a huge step forward towards autonomous driving. It comes as an option in the next-generation ComfortClass and TopClass.
SetraWorld Magazine
On the road to tomorrow.
Entering a new era of assistance systems with Active Drive Assist 2.
On the road to tomorrow.
Entering a new era of assistance systems with Active Drive Assist 2.
All of a sudden, Fabian Reuter collapses at the wheel. After exactly 15 seconds, a cascade of warnings is triggered: amber alert on the central instrumentation, red alert, acoustic signal, the hazard lights flash, and then the Setra TopClass S 516 HDH rolls to a controlled stop within its lane. Reuter, Active Drive Assist project leader at Daimler Buses straightens up with a bounce – all OK. “We test the emergency stop assistant in every bus or coach fitted with Active Drive Assist 2 before delivery,” he explains.
Support on long journeys.
A few minutes later, we are gently cruising on the motorway in the Setra. The Emergency Stop Assist function may be an essential and, for buses and coaches, revolutionary part of the new Active Drive Assist 2. But it’s certainly not the only one. Far more a part of everyday driving is the combination of longitudinal and lateral guidance, the fusion of cruise control with an active steering assistant. The result: partially autonomous driving.
Experts call this level 2 in the five steps towards full automation. Level 2 means: the driver needs to monitor the system and be ready to intervene as needed at any moment. “Active Drive Assist 2 above all supports the driver on long trips because it eliminates the constant need to make slight corrections to the steering. It leaves you feeling notably fresher after a long journey,” Reuter explains. And he knows what he’s talking about: this developer can look back on long years behind the wheel, including as a driver of a tour coach.
Unburdening the driver with automatic lane guidance.
Now, Reuter presses a button to activate Active Drive Assist 2. A green steering wheel symbol lights up on the display – the system has detected the lane markings and is taking over control of lane guidance. What it requires are cameras and the radar sensors used in other assistants. An additional torque sensor determines if the driver’s hands are on the wheel; an electric motor in the steering gearbox takes over the task of staying in lane; a control device carries out monitoring and adjustment processes.
“The coach runs straight as an arrow in its lane.”
“The driver of the coach has three lane position options,” Fabian Reuter notes, “down the middle, offset slightly left or slightly right.” His hands stay on the wheel while the Setra keeps exactly on track with slight adjustments to the steering. It's more accurate than even an experienced driver could manage, and keeps going hour after hour. The assistance system stays strictly between the markings: the high-decker rolls masterfully on, calmly and without any sudden jerky motions.
System optimisation for buses and coaches.
“We developed Active Drive Assist 2 in close collaboration with our colleagues in Trucks,” Fabian Reuter declares. It wasn’t possible to transfer the system directly, however, as coaches and lorries have fundamental differences. Alongside weight and dimensions, these also include subtleties such as the different locations of the now electronically controlled steering gearbox. In addition, the front axle of a bus or coach, with its independent suspension, is very different from the beam axle of a truck.
“Adapting the system was a very laborious process.”
“Adapting the system was a very laborious process,” Reuter asserts. But it paid off, as what was originally a lane warning system has turned into an active lane assistant with steering control. And the variable steering support means manoeuvring is astoundingly simple. Not least, “during turns, the driver benefits from the wheel clearly returning to its zero position,” Reuter says. And it’s true: it works perfectly.
In the right lane all across Europe.
Development and testing involved much more than just adapting and improving functions: “we drove across the entirety of Europe, because lane markings differ in every different country,” Reuter adds. Reliable lane detection is at the very core of Active Drive Assist 2. And the many miles paid off: bus drivers can now rely on the new Active Drive Assist 2 when travelling anywhere in Europe. New Setra coaches with Active Drive Assist 2 can detect lane markings anywhere, from Scandinavia to the Mediterranean coast, effectively supporting drivers on long journeys.
The smart entry into automated coach driving
All assistance systems work together with Active Drive Assist 2: to ensure the most economical driving style possible, the system acts according to the specifications of the Predictive Powertrain Control. The system uses functional extensions based on the tried-and-tested adaptive cruise control and the active lane assist for longitudinal and lateral vehicle guidance. To detect the traffic ahead, Active Drive Assist 2 uses the same advanced radar and camera technology as Active Brake Assist 5.
