Elephant Racing – delivering at peak performance on the race track

Reporting from Elefant Racing e.V. are Sebastian Sartor (COO Driverless), Luca Eisentraut (Chief Operating Officer) and Tim Ehrhart (Treasurer):

In 2021, coronavirus is still very much defining our communal lives. After “Lockdown – everyone stay at home” again in December 2020, we were in constant contact with the University Governing Board to enable work to resume on our FR20 Ragnarök. In mid-January, we were allowed to continue working in the hall in compliance with the applicable rules for practical courses. First up were the annual registration quizzes for each event. This year it was particularly difficult, as the free slots at all events were significantly reduced due to the pandemic and the associated hygiene measures. We decided to race in Switzerland, Germany, and Hungary, and of course hope that the infection figures will go down enough for us to make our driverless debut in Hungary.

Driverless

The possibility of fully autonomous driving is one of the great innovations of our FR20. For this purpose, the vehicle is enhanced with various sensors (3x monocular cameras, 1x stereo camera, dual-antenna global navigation satellite system (GNSS) with integrated inertial measurement unit (IMU), and optical speed sensor), a powerful computing unit, actuators (emergency braking system, electric steering), and an extensive software stack.

To ensure an effective and efficient process of development, we have been talking to experts from ZF Friedrichshafen and the University of Pennsylvania (Penn Electric Racing) every fortnight. Fabian Lüthgens, member of the Driverless Sub-Team, says: “The fact that little Bayreuth has been matching the big teams from Munich, Zurich, and Boston every year is of course something very special, and not to be taken for granted. Without the collaboration of our sponsors that would never be possible. So, we are very happy to be working with Hexagon NovAtel and Leica Geosystems, and to be lining up for the future of motorsport with them.”

Vehicle dynamics

Now that the chassis, steering, brake system, and pedals have already been installed on the car, we have preparing the remaining assemblies for mounting on the car. The arrival of the wheel unit means it can now be mounted on schedule. So, the FR20 should be standing on its own four wheels very soon.

Mechanics

In the area of mechanics, we had to provide a lot of formal documentation. In order to be allowed to participate in the competitions, all vehicle documents must be submitted to the organisers. This enables them to assess whether any infringements of the rules have been committed, and whether there are any safety-related deficiencies. The most important document for proving the safety of the racing car is the Structural Equivalency Spreadsheet (SES). This explains in detail the design and dimensions of the mechanical vehicle components. In addition, all dimensions, test evaluations, and calculations of the components are recorded.

In addition to the SES, the IAD (Impact Attenuator Data) and the SE3D were delivered in March 2021. In the IAD, special attention is paid to the crash element, which represents the front-most part of the vehicle. This must absorb a certain amount of energy in the event of a frontal impact, thereby protecting the driver. The SE3D is a 3D model consisting of the chassis, battery box, and the two roll bars, the main hoop and front hoop.

The headrest, which consists of a CFRP board and a cushion, was also manufactured and attached to the main hoop. Meanwhile, the exact course of the cooling hoses was determined. To protect the driver, firewalls must be placed between them and all components of the tractive system. The tractive system includes the motors, the battery, and the inverters. These firewalls are made of 0.5 mm thick aluminium and a special flame-resistant coating, and must be able to be fitted and removed very precisely.

Electrics

Our electrics team has a very large area of responsibility. The assemblies such as the battery, motor, computer system, and power steering for Driverless are the focus of the individual event. The battery is finished, the wiring harnesses fitted, and all the circuit boards tested, installed in the car, and ready for use. The commissioning of the high-voltage system and the completion of the motor are still to follow. In parallel, the ESF (Electrical Safety Form) was handed in, detailing the complete implementation of all safety components. Finally, preparations for the static disciplines, Cost Report and Design Judging, which are important in all competition categories, will be on the agenda.

Aerodynamics

The newly designed aero is probably the most striking change from last year. After we had implemented and simulated our aero package in accordance with the rules, we went into production. Our toolings were either made out of the polyimide Rohacell, or come directly from our 3D printer. We then apply foil to the finished carbon parts. Accordingly, the diffuser, rear wing, and most of the side pods are already finished. It was noted that the aero package has been a significant additional expense, but this, of course, also came with a 119% increase in downforce.

Prospects

Looking ahead to the next few weeks, we are looking forward to completing the FR20 Ragnarök and to finally starting testing. We are quietly confident that our FR20 will prove its mettle on its first outing at the ZF Race Camp at the end of May 2021.