Just a few years ago, driverless cars and buses zooming around futuristic metropolises were predominantly the stuff of Hollywood sci-fi movies. You may remember Arnold Schwarzenegger being chauffeured by an android in "Total Recall", or Tom Cruise boldly escaping from an autonomous shuttle in the Washington D.C. of 2054 in "Minority Report".
But even today, autonomous driving is already increasingly defining the course of vehicle development. Last year already, on a section of the Autobahn 8 near Stuttgart, Dr. Wolfgang Bernhard, Head of Daimler Trucks and Buses, rode alongside Winfried Kretschmann, Governor of the German state of Baden-Württemberg, in an autonomous Actros truck equipped with the Highway Pilot. With the Mercedes-Benz Future Bus, we are today presenting to you another milestone in autonomous mobility, and our response to the challenges of urban passenger transport. At the heart of this bus is a modified and enhanced version of the Highway Pilot, which is specifically tailored to meet the requirements of city buses and allows semi-automated driving in urban areas: the CityPilot. Being based on the Highway Pilot seen in the Mercedes-Benz Actros, the CityPilot has additional capabilities that are specifically suited for passenger transport in cities.
During development we were able to draw on our vast experience with the Future Truck. Nevertheless there are many specifics that need to be taken into account when it comes to using autonomously driving buses for urban passenger transportation. Important aspects here include recognition of traffic lights and pedestrians, driving across traffic-light-controlled intersections, traveling through tunnels, driving when there is another vehicle ahead in the same lane, approaching and leaving bus stops and the automatic opening and closing of the passenger doors. Like the Future Truck, the Mercedes-Benz Future Bus with CityPilot is not a lab test but, instead, drives on a section of the Bus Rapid Transit (BRT) system in Amsterdam – under real-life conditions. Our goal is a bus in which the driver no longer has to actively control the steering wheel, brakes or gas pedal. This means that the bus must at all times know exactly where it is, what objects and people are around it and what will happen in the next moments – so that it can react appropriately.
To overcome these extremely demanding challenges, the CityPilot system is equipped with a multitude of sensors. The bus has ten cameras, including a stereo camera that allows 3D vision, mirror cams in place of the side mirrors and lane-detection cameras. Radar sensors on the front of the bus scan the area between 10 cm and 200 m ahead of the vehicle. Thanks to WLAN, the bus permanently swaps information with the infrastructure, and it can be located by means of GPS. Just as important as the gathering of data by sensors is the ability of the CityPilot to process this data into an exact image of the vehicle surroundings and to react to these surroundings instantaneously. On top of this, the bus is equipped with electrically controlled Servotwin steering, which enables extremely precise steering maneuvers.
Thanks to its vast array of technology, the bus is able to remain in the middle of the 3.1-meter-wide lane and, even when traveling at its top speed of 70 km/h, can stay within just 20 cm of the lane center. This would be impossible for a human driver to achieve over a long period.
What's more, the bus has the capacity to learn: During a teach-in phase, the cameras record points of reference around the driven route and even the ground conditions, resulting in a model that is as unique as a fingerprint. When the bus later goes into service, it can compare this learned model with the sensor data and determine its position accurate to 8 cm.
The CityPilot controls the vehicle's approach to bus stops with a hitherto unseen degree of precision. During fully automatically controlled braking, the bus stays on track accurate to just 2 cm thanks to its now slowing speed before stopping exactly at the bus stop just centimeters away from the curb. Boarding and alighting is therefore easy and safe for passengers of all ages. At bus stops, the doors open and close automatically as soon as the photoelectric sensors in the door area signal that there are no longer any passengers between the doors.
If there are any pedestrians or obstacles in the bus lane, they are detected by the radar sensors and stereo camera on the front of the bus, in which case the bus brakes to a standstill automatically. In emergencies, the driver can intervene at any time. The CityPilot is deactivated the moment the driver actively steers the vehicle or touches one of the pedals, meaning that the driver always retains full control of the vehicle.
Maiden voyage on the Amsterdam BRT line.
Today the Future Bus with CityPilot is celebrating its world premiere. Its stage will be Airport Line 300 in the Dutch city of Amsterdam. Measuring almost 40 km, the route is Western Europe's longest BRT line, serving more than 125,000 passengers per day on average. With a journey time of approximately 30 minutes, we will be traveling along a 19 km section of route between Amsterdam-Schiphol Airport and Haarlem, where there are eleven bus stops. Ahead of us lies a demanding route with tight bends, no barriers to the oncoming bus lane, 22 sets of traffic lights, and three tunnels. These challenges impressively show just what the Future Bus with CityPilot can do:
It navigates the tight bends with the aforementioned precision of the CityPilot semi-automatically. The radar sensors and cameras even make it possible to drive through tunnels, which are a major hurdle for autonomous driving since GPS reception is not always a given. These sensors and cameras keep the bus constantly informed about the exact distance to the tunnel walls. The Vehicle to Infrastructure-System (V2I) ensures that the bus is in permanent contact with the BRT infrastructure. As an example, the CityPilot can inform traffic lights of its position from around 300 m away via WLAN, whereupon the traffic lights can prioritize the bus and allow it to pass through quickly. Should this not be possible due to an excessive volume of traffic, the infrastructure prompts the bus to reduce its speed to ensure efficient and smooth operation at all times. Should the WLAN signal be unavailable at any point, the front cameras on the bus ensure that the bus can still react to traffic-light signals.
On the whole, it can be said that BRT lines – like the one in Amsterdam – are ideally suitable for autonomously driving buses. Bus Rapid Transit lanes are separate from other traffic lanes, the route is always the same, and the bus always encounters the same clear-cut situations at barrierless bus stops and hubs. In this respect, the Future Bus with CityPilot fits in perfectly with our concept of urban mobility for the future. Our designs focus on the bigger picture, and we develop complete transportation systems.
We all benefit from the bus of the future
Today marks a dream come true for us. Our vision, our bus of the future, is taking its first trip before the eyes of the world on the streets of Amsterdam. We can hardly wait to see the technological possibilities the Future Bus with CityPilot opens up for series-production vehicles. We are convinced that we will all benefit from them: From the efficiency, environmental compatibility and safety. On top of this, the drivers encounter far less stress and, consequently, will be fully focused and alert should they ever be called into action. Bus operators save on running costs thanks to a driving style that boosts efficiency and reduces component wear. And, for passengers, the journey is safer, quicker and more comfortable than ever before.
So there is much justification for the claim: Our Mercedes-Benz Future Bus with CityPilot is the most advanced bus that ever hit the road!