Setra plays it safe: The new milestones Active Brake Assist 5 and Active Drive Assist 2 – the path to self-driving coaches

• Active Brake Assist 5: A milestone in safety development
• Active Drive Assist 2: the smart entry into automated driving
• Numerous additional new functional features enhance safety

Setra is synonymous with bus safety. Many safety and assistance systems have made their debut in a Setra coach – the range of innovations extends from the retarder to the anti-lock braking system and Sideguard Assist, to name just a few. Setra's integral safety concept helps proactively prevent accidents. It protects both passengers and the driver, taking into account vulnerable road users as well. The next generation of coaches underscores high safety standards with spectacular innovations in the field of assistance systems. The Setra ComfortClass is based on an enhanced electrical/electronic platform. "It forms the foundation for the latest generation of assistance systems, among other things. With these systems, the Setra ComfortClass sets industry standards in its segments and beyond. The optional Active Drive Assist 2 enables semi-automated driving in a coach for the first time. The standard Active Brake Assist 5 (ABA 5) is the world's first emergency brake assistant that can respond with a full brake application to moving and stationary pedestrians.

Active Drive Assist 2: the intelligent introduction to automated driving

Accelerating, braking, maintaining distance, steering, staying in lane and even emergency braking – the new Active Drive Assist 2 represents a decisive step on the path toward self-driving coaches. The Active Drive Assist 2 actively supports the driver in maintaining distance and staying in lane through the combination of various assistance systems. The system can brake and accelerate the vehicle and keep it in lane through active steering of the vehicle. It also combines the functions of individual systems in a unique way, already enabling semi-automated driving in all speed ranges today.

With Active Drive Assist 2, all assistance systems work hand in hand and support each other: Active Drive Assist 2 operates according to the specifications of Predictive Powertrain Control (PPC) in order to ensure the most economical driving style possible. For the longitudinal and lateral control of the vehicle, the system uses functional extensions based on proven Adaptive Cruise Control (ACC) and Lane Keeping Assistant. Furthermore, the Active Drive Assist 2 leverages the same advanced radar and camera technology as the Active Brake Assist 5 (ABA 5) for detecting the traffic ahead. An emergency stop function has also been implemented. This brings the vehicle to a halt through a moderate, automated braking action if the driver stops responding.

An essential component of the Active Drive Assist 2 is the active lateral control within the lane, achieved through the active steering assistant with an electric motor supporting the hydraulic steering, plus integration with the longitudinal control of the Adaptive Cruise Control (acceleration/braking/distance maintenance) by fusing radar and camera information.

With the active steering assistant, the Active Drive Assist 2 keeps the coach within the lane at the driver's set desired position, in addition to the activated Adaptive Cruise Control. The driver can choose between three settings: The bus or coach can either drive precisely in the centre of the lane or, depending on the width of the lane, slightly offset by ten to 20 centimetres to the left or right. The system significantly relieves the driver by taking over the majority of the continuous minor steering adjustments needed to stay in lane. Just like ART, active lateral guidance by Active Steering Assist is active across the coach's entire speed range from 0 to 100 km/h. System requirements: The lane must be clearly marked with visible lines on both sides.

A green steering wheel symbol on the central display indicates to the driver that the active steering assistant is supporting them in the lateral control of the vehicle. If the driver wishes to deactivate the comfort assistance due to the current traffic situation, they can do so.

Even when the Active Drive Assist 2 is deactivated, the proven Adaptive Cruise Control (ACC) continues to handle longitudinal control of the vehicle,in tandem with the Predictive Powertrain Control (PPC) for predictive cruise control. The Adaptive Cruise Control adjusts the speed of the bus or coach by slowing it down before getting too close to the vehicle in front and then accelerating back up to the speed set by the driver. If necessary, it can even bring the coach to a complete stop with partial braking.

Active Drive Assist 2 was developed for driving on motorways and similar roads, which is why a minimum lane width is required. If system limits, such as unclear lane markings, a lane that is too narrow or bend radii that are too tight, are reached, the system becomes passive. This is accompanied by a warning to the driver, signalled by a corresponding display in the cockpit.

Despite the assistance provided by the Active Drive Assist 2, the driver always remains in charge. If the driver takes their hands off the steering wheel, a cascade of warnings is triggered in line with legal requirements (hands-off warning cascade). After°15°seconds, the assistance system warns the driver with a yellow display, then with a red display in the instrument panel and additionally with audible warnings at ever shorter intervals until a continuous tone is emitted.

If 60 seconds have elapsed since the start of the hands-off warning cascade without the driver having placed their hands back on the steering wheel, the emergency stop function is activated. This initiates a speed reduction by releasing the accelerator for one second. This is followed by the speed reduction. The emergency stop function now assumes control of the vehicle within the system limits in order to keep it in lane. The headlamps are activated and the hazard warning lights are activated 5 seconds before the hands-off warning cascade ends to warn the traffic behind and the vehicle is moderately braked to a standstill. When the vehicle is stationary, the electric parking brake is activated and the hazard warning system continues to flash. While the emergency stop function is intervening, the driver is continuously informed of the emergency stop and the possibility of overriding by a continuously audible beep and a visual warning in the display and can abort the process using a kickdown.

Active Brake Assist 5: A milestone in safety development

The unique emergency braking assistance system Active Brake Assist 5 – ABA 5 for short– is another milestone in safety development. Introduced for the first time in a coach in 2008, the continuously improved Active Brake Assist reaches a higher level of performance in its fifth generation. ABA 5 is the first system to combine radar and camera technology. The standard assistance system in the ComfortClass can perform an automated full braking manoeuvre, bringing the vehicle to a complete stop, when encountering stationary and moving obstacles, just like the previous ABA 4 system. However, ABA 5 is the world's first emergency brake assistant for coaches and buses that can also perform an automated full braking manoeuvre on both moving and stationary pedestrians at speeds up to 50 km/h.

Active Brake Assist 5 can detect both moving pedestrians and individuals who come to a sudden stop. Here's how: If there is a risk of collision with a pedestrian, the Active Brake Assist 5 provides visual and audible warnings to the bus driver while initiating a partial braking with up to 50 percent of the maximum braking force. If the driver fails to respond, an emergency braking is automatically applied until the vehicle comes to a complete stop.

Numerous other new functional features also enhance safety

Other innovations, such as the electronic parking brake and the 360° camera system, significantly increase safety in addition to improving functionality and user-friendliness. The same applies to the new, even more powerful full LED headlamps and high-beam assistant (see separate text on cockpit and design).