High-precision measurement technology – essential for success
At Hockenheim, where the season's most important and most fiercely-contested race is staged, StarkStrom secured an honorable fourth place as well as the world record for acceleration. Prof. Dr.-Ing. Carsten Markgraf, of the Faculty of Electrical Engineering at UAS Augsburg, stresses the importance of this result: 'It's a remarkable success for a small university like Augsburg, pitted against teams from giants such as the Technical University of Munich (TUM) and the Swiss Federal Institute of Technology Zurich (ETH).' An achievement of this magnitude calls for a degree of technological expertise in fields such as environmental perception and path planning for autonomous driving. For these purposes, the StarkStrom racing car is equipped with LiDAR and camera systems: data from them is merged to determine the lie of the track and keep the vehicle on course. In the 2018 season, the team chose a D-GPS module to determine the car's absolute position; however, this device starts up slowly and is quite likely to fail. 'But periods when there is no GPS signal can be bridged over very well with data from the Kistler sensor,' according to Christian Scheglmann, who is also studying for a Masters in Applied Research and is the team member responsible for camera systems.
What are the factors behind a success on this scale? First and foremost: committed students who dedicate their time to applied research in electromobility as members of StarkStrom Augsburg, which is a registered nonprofit association. The club is supported by sponsorships from companies who provide financing and equipment, helping the young engineers to put their know-how into practice on the racing track. Pechinger explains how the team views Formula Student: 'We're proud of the record, of course, but that's not the main thing – above all, the objective is to learn something new. And that's why we chose Formula Student's motto: 'It’s not about getting faster, it’s about getting smarter.''
Young engineers shoulder responsibility
Prof. Markgraf is available to advise the students, but they take on most of the responsibilities themselves within a structure based on corporate lines. The core team comprises electrical engineers, mechatronics and IT specialists and – last but certainly not least – a business economist. 'Many students attain new levels of achievement in the team, and they open up wider horizons in terms of personal development. They tackle demanding assignments – most of them are directly related to the subjects they study, but they gain deeper insights by putting their knowledge to practical use,' Prof. Markgraf observes.
The racing car, a miniaturized classic single-seater (or 'monoposto'), can also be steered by a driver if necessary; it is built entirely on site at Augsburg. The functions for autonomous driving are added to the mechanical and electronic structure, as Scheglmann points out. 'Driverless racing cars are far more complex than their conventional counterparts. Many features simply have to be included as requirements, and then the extra functionalities are added on top.' As regards Formula Student, Pechinger adds: 'Strict requirements have to be met before you're even allowed to enter the race – there's a braking test, for instance. Many teams already fail at this hurdle. And after you've spent so many hours building a racing car, you don't want it to crash into a wall!'
High precision, simple integration, minimal drift
Kistler's Correvit SFII racing sensor supplies the current speed (x and y) every 5 ms via CAN bus. In combination with the IMU, the vehicle's position relative to the starting point can be calculated every 2 ms. This is more than sufficient for the Acceleration and Skid Pad disciplines, where StarkStrom is regularly among the best contenders. 'The sensor was mounted on the vehicle with a special fixture in less than half a week,' Scheglmann recalls. 'At the beginning, we weren't sure what kind of value the sensor was supplying, but then we realized that we only needed to integrate it once. In fact, integration was really easy; the values are available quickly, and it all works very reliably.' Pechinger adds: 'The sensor is very accurate and there is virtually no drift, so it's almost 100% reliable over shorter distances.'
This is why the team plans to eliminate D-GPS from the setup entirely for the 2019 season. Depending on requirements, navigation will then be implemented solely with Kistler measurement technology and the IMU, or with Kistler, IMU and SLAM (Simultaneous Localization and Mapping, now in development). The new setup will undergo intensive testing on the asphalt in spring 2019. Formula Student will also continue to evolve – new and more challenging disciplines will set the bar even higher. The ultimate aim is not only for driverless cars to compete on the racetrack, but also for them to drive on the roads at some point in the future. Prof. Markgraf concludes: 'Kistler's racing sensor gives our students a critical resource that allows them to continue developing their vehicle's capabilities. Members leave the team from time to time, and new faces appear as well – but it's clear that development is ongoing: I'm excited to see what StarkStrom will achieve in the coming years.'