Piloted Driving Supported by GIGATRONIK

Steering, accelerating, braking: with piloted driving the car does all the work itself. The driver can take control, but doesn't have to. This is made possible by the vehicle's extremely precise road orientation and its exact control, even when pushed to the limit. Audi is right up-to-date with this trend in the world of cars - thanks to support from GIGATRONIK.

Beweis erbracht: Audi RS 7 piloted driving concept fährt beim DTM-Finale in Hockenheim fahrerlos am Limit. Foto: Audi
Audi RS 7 piloted driving concept, Ascari 2014. Foto: Audi

Hockenheimring, at the final of the Deutsche Tourenwagen Masters in October 2014: an Audi RS 7 roars up to 240 km/h along the straight, and the crowd watch in amazement - there's nobody at the wheel. The car knows the straight well, it knows when to speed up and when to brake, it can steer itself and follows the perfect racing line right up to the finish.

Ascari Race Resort, Spain, a few weeks later: car journalists are invited to experience how the Audi RS 7 piloted driving concept drives around the circuit at more than 200 km/h. Over crests and dips, around narrow chicanes and a steep curve. For the self-driving car it's a very demanding course because there are extreme forces acting on the tyres, brakes and body, and the vehicle controls must react accordingly.

At both events the Audi successfully showed how far the development of piloted driving has already come. As with more traditional vehicles, motor racing offers the opportunity to test new technologies to the limit. The Audi RS 7 piloted driving concept corresponds largely to the standard vehicle. Its electromechanical power steering, its brakes, its motor and the eight-step tiptronic gearbox, which guides the electromechanical quattro drive system, are now automatically controlled. Many key elements of the system have been developed by GIGATRONIK engineers in partnership with Audi.

Ultra-complex Techniques for Piloted Driving

When piloted driving is pushed to the limit, it's essential for the car to know the course well. A precise model of the course layout is created during test drives. A special tool uses this information to calculate the ideal racing line. To orient itself on the course the car uses corrected GPS signals, which enable it to pinpoint its position to within 5 and 10 cm. These centimetre-exact GPS figures are transmitted to the car in accordance with automotive standards by WLAN and additionally by high frequency radio. Cameras at the front and rear of the car build up a 3D image of the drive, and compare this image constantly and in real time with the stored image information. In each and every one of the countless individual images, the system searches for hundreds of familiar landmarks, taken for example from plans of roadside buildings, which offer additional location information. The vehicle is equipped with a robust real-time prototype control unit, which can handle large amounts of data quickly at high speeds because of its extremely high frequency. Two separate computers support comparison with maps and images.

The on-board network's comprehensive diagnostics capacity, coupled with highly precise controls of all driving related actuators, enables the Audi RS 7 piloted driving concept to drive safely even at high speeds. GIGATRONIK have developed a longitudinal dynamics regulator for the Audi RS 7, which like cruise control sets the vehicle to the speed calculated by the prototype control unit, and adapts to even the tiniest differences between the target state and actual state. One part of the system is a drive train coordinator, which controls the motor, gearbox and brakes to achieve the required result. The system responds to external factors such as road condition, road elevation profile, weather, or vehicle condition. The electronic braking regulator, also developed by GIGATRONIK, continually calculates the braking power of each individual wheel during the braking phase, depending on the optimal vehicle deceleration. An additional stopping regulator applies the brakes when required to bring the vehicle to a safe halt as soon as the target coordinates are reached. The function controller, which among other things controls vehicle initialisation when the system is activated, was created by the engineers at GIGATRONIK's Ingolstadt facility as well. In order to visualise the complex development project the engineers modelled the project in the preliminary stages using simulation software, which allowed them to test its technical feasibility.

During the whole development phase the GIGATRONIK engineers were part of the team, and also took part in the test-drives at the Oschersleben Motorsport Arena and at the Hockenheimring. The GIGATRONIK engineers spent three weeks in the autumn of 2014 at the Spanish Ascari racetrack, looking after the vehicle and making sure it was ready to use. At the event itself 'spotters' observed the driverless vehicle, and kept it in their sight at all times.

Milestones for the Future of Cars

With the Audi RS piloted driving concept the manufacturer has, in its own words, brought the sportiest piloted driving car in the world to the racetrack. Testing the car to the physical limit offers valuable insights that can be used for developing series production models. For example, automatic obstacle-avoiding functions for critical situations, or piloted driving in traffic or when parking. GIGATRONIK has been working with Audi for many years on these projects and has been a key part of developing the assistance systems. With its extensive experience in electronics and information technology, the company is an in-demand development and consulting partner for the automobile and other industries.

Florian Rubländer
Corporate Communications