Volvo Presents System for Integrating Autonomous Cars into Traffic

Autonomous cars will give drivers a break.

Volvo Cars has a complete system solution that makes it possible to integrate self-driving cars into real traffic, with ordinary people in the driver’s seat. The automaker presented its planned system in an online press conference Feb. 19.

“We are entering uncharted territory in the field of autonomous driving,” said Peter Mertens, senior vice president of Research and Development, Volvo Car Group. “Taking the exciting step to a public pilot, with the ambition to enable ordinary people to sit behind the wheel in normal traffic on public roads, has never been done before.”

As the Drive Me project enters its second year, Volvo is moving toward its goal of placing 100 self-driving cars in the hands of customers on selected roads around Gothenburg by 2017. The public pilot — a collaboration between legislators, transport authorities, a major city and a vehicle manufacturer — is a central component of Volvo’s plan to achieve sustainable mobility and ensure a crash-free future.

Early prototype cars are now being tested on the DriveMe route in and around Gothenburg, Sweden.

Volvo’s production-viable autonomous driving system is based on a complex network of sensors, cloud-based positioning systems and intelligent braking and steering technologies.

“Autonomous driving will fundamentally change the way we look at driving. In the future, you will be able to choose between autonomous and active driving,” Mertens said. “This transforms everyday commuting from lost time to quality time, opening up new opportunities for work and pleasure.”

Volvo’s autopilot system is designed to be reliable enough to allow the car to take over every aspect of driving in autonomous mode, Volvo said. The technology advances a crucial step beyond the automotive systems demonstrated so far since it includes fault-tolerant systems, the carmaker said.

“It is relatively easy to build and demonstrate a self-driving concept vehicle, but if you want to create an impact in the real world, you have to design and produce a complete system that will be safe, robust and affordable for ordinary customers,” said Erik Coelingh, technical specialist at Volvo Cars.

The main challenge is to design an autopilot that is robust for traffic scenarios as well as for technical faults that may occur. The driver can’t be expected to suddenly intervene in a critical situation. Initially, the cars will drive autonomously on selected roads with suitable conditions, such as without oncoming traffic, cyclists or pedestrians.

Volvo’s system generates exact positioning and a complete 360° view of the car’s surroundings through a combination of radars, cameras and laser sensors. A network of computers processes the information, generating a real-time map of moving and stationary objects in the environment.

“Making this complex system 99 percent reliable is not good enough. You need to get much closer to 100 percent before you can let self-driving cars mix with other road users in real-life traffic,” Coelingh said. “Here, we have a similar approach to that of the aircraft industry. Our fail-operational architecture includes backup systems that will ensure that the autopilot will continue to function safely if an element of the system were to become disabled.”

For example, the probability of a brake system failure is very small, but a self-driving vehicle needs a second independent system to brake the vehicle to a stop, because it is unlikely that the driver will be prepared to press the brake pedal.

On the road, the complete technology solution is designed to handle even the most complicated scenarios, from smooth commuting to heavy traffic and emergency situations, Volvo said. “Just as good drivers would, potentially critical situations are approached with sensible caution. In a real emergency, however, the car reacts faster than most humans,” Coelingh said.

When autonomous driving is no longer available — because of weather, technical malfunction or the end of the route has been reached — the driver is prompted by the system to take over again. If the driver is incapacitated for any reason and does not take over in time, the car will bring itself to a safe place to stop.

Volvo expects that autonomous driving could cut fuel consumption, improve traffic flow, and open up possibilities for urban planning and more cost-efficient investments in infrastructure.

“Developing a complete technological solution for self-driving cars is a major step. Once the public pilot is up and running, it will provide us with valuable knowledge about implementing self-driving cars in the traffic environment, and help us explore how they can contribute to sustainable mobility,” Coelingh said. “Our smart vehicles are a key part of the solution, but a broad societal approach is vital to offer sustainable personal mobility in the future. This unique cross-functional cooperation is the key to a successful implementation of self-driving vehicles.”

Drive Me system components:

The 76-GHz frequency-modulated, continuous wave radar is placed in the windscreen and combined with a camera to detect objects on the road. Four radars behind the front and rear bumpers locate objects in all directions. Long-range radars in the rear ensure a good rearward detection of vehicles in parallel lanes.

Sensor technologies. Volvo Cars is developing a holistic solution that generates exact positioning and a complete 360-degree view of the car’s surroundings. This is achieved by a combination of multiple radars, cameras and laser sensors. A redundant network of computers processes the information, generating a real-time map of moving and stationary objects in the environment.

Precise positioning is based on this surround information together with GPS and a high-definition 3D digital map that is continuously updated with real-time data. The system is reliable enough to work without requiring driver supervision.

Combined radar and camera. The combined 76-GHz frequency-modulated continuous wave radar and camera placed in the windscreen is the same as that in the new XC90. This system reads traffic signs and the road’s curvature and can detect objects on the road such as other road users.

Surround radars. Four radars behind the front and rear bumpers (one on each corner of the car) are able to locate objects in all directions. By sweeping both left and right, transmitting waves that bounce off signs, poles, and tunnels, they monitor a full 360-degree around the car.

360-degree surround vision. Four cameras monitor objects in close proximity to the vehicle. Two are under the outer rear-view mirrors, one is in the rear bumper and one is in the grille. Besides detecting objects at close range, these cameras monitor lane markings. The cameras have a high dynamic range and can handle quick changes in lightning conditions, such as when entering a tunnel.

Multiple beam laser scanner. This sensor system is placed in the front of the vehicle, below the air intake. The scanner can identify objects in front of the car and ensures very high angle resolution. It can also distinguish between objects. The laser sensor has a range of 150 meters for vehicles and covers a 140-degree field of view.

Trifocal camera. A trifocal camera placed behind the upper part of the windscreen is three cameras in one, providing a broad 140-degree view, a 45-degree view and a long-range, yet narrow, 34-degree view for improved depth perception and distant-object detection. The camera can spot suddenly appearing pedestrians and other unexpected road hazards.

Long-range radars. Two long-range radars placed in the rear bumper of the car ensure a good rearward field of view. This technology is useful when changing lanes because it can detect fast-moving vehicles approaching from far behind.

Ultrasonic sensors. Twelve ultrasonic sensors around the car are used to identify objects close to the vehicle and support autonomous driving at low speeds. The sensors are based on the technology used for current park-assist functions enhanced with advanced signal processing. This technology is useful for detecting unexpected situations, such as pedestrians or hazards on the road close to the car.

High-definition 3D digital map. A high-definition 3D digital map provide the vehicle with information about the surroundings, such as altitude, road curvature, number of lanes, geometry of tunnels, guard rails, signs, and exits. The position geometry is in many cases at centimeter level.

High-performance positioning. The high-performance GPS is one part of the positioning control that is enhanced by a combination of an advanced GPS, a three-degrees-of-freedom accelerometer and a three-degrees-of-freedom gyro. By matching the 360-degree image created by the multitude of sensors with the map image, the car will get the information about its position in relation to the surroundings.

By combining the information from the sensors and the map, the Drive Me car is able to choose the best course in real time, factoring in variables such as the curvature of the road, speed limit, temporary signs and other traffic.

Cloud services. The cloud service is connected to the traffic authorities’ control center. This ensures that the most up-to-date traffic information is always available. Control center operators also have the ability to tell the drivers to turn off the autonomous drive mode if necessary.