Start, accelerate, brake, corner: the race car from the GreenTeam at the University of Stuttgart drives along a course marked out with traffic cones. What’s missing is the driver. The GreenTeam has developed a self-driving race car, with which it plans to enter the Formula Student engineering design competition in 2019 in the new category for autonomous vehicles. So far, 26 teams from German universities have entered a driverless vehicle.
Since 2015, the GreenTeam has worked on creating a driverless vehicle as well as an electric vehicle. The project was launched by GreenTeam alumni. “We actually signed up last year, but our race car had a lot of problems getting started. That’s why we couldn’t take part in the competition”, explains master’s student Christian Witte, leader of the Driverless project. “We’re getting this year off to a flying start.”
Some of the students took a semester off to be part of the GreenTeam, and spent roughly a year concentrating on developing, producing and racing the vehicle. They share a building at the campus Vaihingen with the racing team, which has a workshop and desks. “There’s always somebody there”, says Witte, who studies Electrical Engineering and Information Technology at the University of Stuttgart. “We spend a lot of time with each other here.” The members work full-time on the project, depending on which task they are working on. A pizza oven, coffee machine and the ice cart in summer help keep the team going throughout the day. A total of around 65 students are involved in the GreenTeam, 16 of which are responsible for the driverless vehicle. The GreenTeam’s race car is based on their old electric car from the previous season.
How exactly does the driverless vehicle work? “The car behaves according to the motto ‘see, think, act’”. It collects and processes data and reacts based on that”, explains the 25-year-old. A lider system, a very precise laser scanner, scans what’s going on around the vehicle while it’s driving, recognizes objects and works out how far away they are. Also, two to four cameras on the vehicle record the color and size of the traffic cones which mark out the route. Additional sensors measure the acceleration and speed of the vehicle, among other things.
The data regarding the location and behavior of the vehicle on the unfamiliar course is processed as part of the “think” stage. This is done using the complicated Simultaneous Localization and Mapping (SLAM) algorithm. “One of our mathematicians worked on this for two years. That’s at the heart of our vehicle.” Put simply, the algorithm works out the position and direction of the vehicle in a coordinate system and creates a map at the same time. As soon as the map is established, a route is calculated which the vehicle then takes.
“Overall, we’re happy with the work we’ve done on this year’s vehicle so far.” Production began after Christmas, and the GreenTeam and racing team will present their race car to the public in April 2019. The races in the Formula Student competition begin in June. “There’s a real competitive spirit at the events but the teams do still help each other out.” The atmosphere, the feeling of community and the teamwork are what impresses Witte so much about the competitions. The driverless team has a clear goal for this season. “We want to get into the top 3.”
The Formula Student Germany also intends to focus on driverless cars in the future. The organizers announced a few weeks ago that as of 2021, the acceleration competition, which tests how fast a car can accelerate over short distances, will only be open to autonomous vehicles, whether gasoline-powered or electric. In 2022 this requirement will also be extended to the skidpad course, which is made up of a figure of eight. “This is a real challenge for colleagues with gasoline-powered vehicles. We’re going to have to do some restructuring within the GreenTeam and the racing team.” The driverless team has already promised that it will support the racing team. “Our knowledge as driverless experts is now in demand”, says Witte.
The Formula Student is an international engineering design competition for students, which has been awarded on an annual basis since 2006. The competitions take place both in Germany and further afield, for example in Hungary, Austria and at the Hockenheim race track. The different dynamic disciplines include the skid pad around a figure of eight, an acceleration test, autocross (a slalom course with barriers), an endurance race, and energy efficiency. The team’s overall performance in designing the vehicle is also assessed. This includes disciplines such as presenting their business plan and cost report.