Whether driving through tunnels with changing light conditions, crossing traffic lights, monotonous routes and pale markings, speeds of up to 70 km/h, other road users or driving on embankments: For human drivers, there are many factors that are highly stressful. But these are also a real challenge for self-driving vehicles. Scientists at the Research Center for Information Technology at the Karlsruhe Institute of Technology (FZI) have helped Daimler to automate such a journey without the intervention of a safety driver - and with a 12 m long bus. The new concept for the city bus of the future was presented at the IAA Commercial Vehicles trade fair in Hanover in September 2016.

At its world premiere in July 2016, the Mercedes-Benz Future Bus showed what an autonomous city bus could look like in local transport. The vehicle, based on a Mercedes-Benz Citaro, mastered a 20-km section of the longest bus rapid transit line in Europe with the so-called CityPilot in shuttle mode. The bus drove reliably and confidently for three days on the bus express lane between Amsterdam Schiphol Airport and the city of Haarlem without any intervention from the safety driver.

There are various hurdles for autonomous driving, such as poorly distinguishable environmental features, weak markings, changing light and weather conditions and driving through tunnels. However, new sensor concepts and robust localization make safe driving possible. Robust localization means that a vehicle knows exactly where it is at all times with absolute reliability; a basic prerequisite for autonomous driving. The human driver sees the traffic situation and can draw on his or her experience. In contrast, a self-driving vehicle must replace personal experience with sensors and algorithms. A 12-metre-long bus in particular, which unloads and commutes, is difficult to keep on track automatically.

To enable the bus to drive automatically, the scientists are therefore relying not just on one type of sensor technology such as lane cameras, but on the fusion of several sensor data. By intelligently merging all the information from cameras, sensors and signals, as well as through the driving system's learned knowledge, localization becomes so precise that the Future Bus can drive with centimetre accuracy; a feature that is particularly necessary on the boarding ramps at bus stops and in oncoming traffic. The system developed by the FZI for localizing the bus is highly complex and was tested before the world premiere on the Bus Rapid Transit route both on the computer and with a standard bus without special modifications as a test vehicle and with the actual demonstration vehicle.