Testing times

While virtual race events have kept us entertained during the COID-19 restrictions, the use of highly advanced simulators have also allowed race teams to stay ‘up to speed’ as they prepare for real racing to get underway once again.

For Audi, the high-tech system used to prepare its Formula E team is able to duplicate the vehicle behaviour of the Audi e-tron FE06 almost exactly, making it a real racing experience for the drivers. While for the engineers, the data retrieved from a simulator is invaluable in setting up the car for optimal performance.

“Between the race events, simulation is one of our core tasks and is the most important tool for our drivers and technicians to prepare for the next race,” says Tristan Summerscale, Formula E project leader at Audi. Prior to the restrictions, the Formula E championship held its races at one-day events around the world, for the most part on specially designed street circuits. 

After an E-Prix, the racing cars from all of the teams are loaded and transported together to the next venue. “Since the hardware of the vehicles may not be changed during the current racing season, we can only make our cars more competitive if we constantly improve our preparation, set-ups and software,” Summerscale explains. For this reason, we carry out intensive analysis after each race. 

The most important factors influencing the performance of Formula E cars, which are mostly uniform with the exception of the drivetrain, are the suspension set-up, tyre performance and battery management for the electric drivetrain. 

All of the information that gets digitally recorded during practice, qualifying and the races of the two Audi Formula E racing cars gets evaluated in great detail. “The key to data analysis is to exactly identify each weak point and use it to develop the right improvements to gain more speed for the next race,” says Summerscale.

Audi’s dynamic driving simulator was installed in Audi Sport’s HQ at Neuburg in 2018 and is an integral part of getting the Audi e-tron FE06 ready for the next race.

At these simulator sessions, the staff includes the drivers from Audi Sport ABT Schaeffler, operational engineers from Audi Sport, the operational team ABT Sportsline and, depending on the focus, also a specialist engineer from Audi. In addition, there is the Audi engineer responsible for the operation of the simulator, the so-called “test bench operator.”

The drivers sit in a cockpit that is mounted on computer-controlled, three-dimensionally movable stilts. These are located on a platform that can also be moved to three levels with a total of nine degrees of movement. This design gives the driving simulator its dynamic aspect. “In contrast to the static simulator, the movements of the vehicle are simulated in the dynamic simulator,” explains Bastian Göttle, who is responsible for co-ordinating the driving simulator at Audi. 

The simulator has an active seat and active seatbelts inside the racing cockpit and the tensile and compressive forces generated while driving are realistically transmitted to the driver, together with the acceleration and deceleration of the simulator, which can be up to 3.5 times the forces of gravity. 

The driver sits in a realistic monocoque, with steering wheel, pedals and seat all identical to the real racing car. The virtual circuit that is driven on is projected onto a 240-degree screen. “Thanks to the optimised graphics, we are now even closer to reality,” says Audi factory driver Lucas di Grassi. Speakers play the original sounds of the Formula E car and in the control room next door, the technicians follow every driving manoeuvre and every output from the vehicle on a series of monitors.

At Audi Sport ABT Schaeffler, preparation for the next race in the driving simulator begins with the follow-up to the previous Formula E race. “We enter the data of the chassis set-up that was actually used and the tarmac and air temperatures that were present into the simulation. With this, we let one of our drivers virtually complete our last race and the qualifying session,” says Summerscale. 

“On circuits where we have driven several times and have collected a lot of real data, we achieve an even more exact match with reality in our driving simulations.”

It is not uncommon in Formula E to have circuits that are either completely new or have undergone major layout changes so that practicing the tracks in the driving simulator is another important task for the drivers before every E-Prix. 

“Getting used to tracks within a few laps works very well for me in the simulator. This saves me a lot of valuable time at the real venues on race days, when practice, qualifying and the races take place in quick succession,” says Lucas di Grassi.

The simulator also makes it possible to run through all of the possible suspensions options, looking at springs, dampers, stabilisers and camber adjustment.

The level of the tyre simulation is even more important given that in qualifying for the race, the drivers only have one lap to set the time that determines their position on the grid. 

But the test objective with the highest priority on the preparation program of the Audi Formula E project is energy management. That means finding the best possible driving strategy for the race and of utilising the available 52 kWh of energy from the lithium-ion battery in the Audi e-tron FE06 to cover the race’s specified distance (45 minutes plus one lap). 

In the driving simulator drivers can try different racing scenarios in terms of the available energy, with up to three different motor outputs which are available during the races – 200kW (272 hp) for normal running, 235kW in attack mode and 250kW via FanBoost (a short power increase for the five drivers who receive the most votes from the fans via the internet).

For Tristan Summerscale and his team, the dynamic simulator is a key tool for more victories and titles.

“Every single element of the 2000-piece puzzle making up our Formula E car that has been optimised a little bit helps us to move forward. In the same way, each of our advances in the driving simulator makes a contribution to perhaps achieving the decisive 10th of a second in the end.”