Opportunities for real-world testing are limited in Formula E, especially in the current climate. We take a look at Audi’s drive for development and preparation of its purely electric racing cars via its dynamic driving simulator.
Audi’s high-tech system is capable of reproducing the behaviour of its e-tron FE06 virtually and realistically, offering a true representation of its on-track behaviour in any number of scenarios for Lucas di Grassi and Rene Rast.
For the engineers from Audi and the Audi Sport ABT Schaeffler team, the complex technical demands in-car and on-track in Formula E are becoming increasingly clear.
Collecting and evaluating data
“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.
After an E-Prix, all 12 teams’ cars 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 focal points for development 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 in races by the pair of e-tron FE06 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.
Into the sim
Staff from Audi Sport ABT Schaeffler, operational engineers from Audi Sport, the team ABT Sportsline and, depending on the focus, a specialist engineer from Audi, take part in the team’s simulator sessions.
In addition, there is the Audi engineer responsible for the operation of the simulator, the so-called “test bench operator”. This way of working has been in-place at the motorsport headquarters of Audi Sport in Neuburg an der Donau since 2018.
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 freedom.
This design gives the driving simulator its dynamic aspect. “In contrast to the static simulator, the movements of the vehicle are accurately conveyed by the dynamic simulator,” explains Bastian Göttle, who is responsible for coordinating the driving simulator at Audi. The driver’s cell used corresponds exactly to that of the real e-tron FE06.
The simulator has an active seat and active seatbelts inside the racing cockpit, allowing forces generated while driving to be realistically transmitted to the driver together with the movement of the simulator, which can exert 3.5g on the driver.
The driver sits in a realistic monocoque, with a steering wheel, pedals and seat identical to their real racing car. The virtual circuit that is driven on is projected onto a wraparound 240-degree screen.
“Thanks to the optimized graphics, we are now even closer to reality,” says Audi factory driver Lucas di Grassi, the 2016/2017 Formula E champion.
Speakers play the real sounds of the Formula E car, and in the control room next door, technicians follow every driving maneuver and every output from the vehicle on a series of monitors.
The simulator has an active seat and active seatbelts inside the racing cockpit, allowing forces generated while driving to be realistically transmitted to the driver together with the movement of the simulator, which can exert 3.5g on the driver.
The driver sits in a realistic monocoque, with a steering wheel, pedals and seat identical to their real racing car. The virtual circuit that is driven on is projected onto a wraparound 240-degree screen.
“Thanks to the optimized graphics, we are now even closer to reality,” says Audi factory driver Lucas di Grassi, the 2016/2017 Formula E champion.
Speakers play the real sounds of the Formula E car, and in the control room next door, technicians follow every driving maneuver and every output from the vehicle on a series of monitors.
Virtually any scenario
At Audi Sport ABT Schaeffler, preparation for the next race in the driving simulator begins with a follow-up to the previous Formula E race.
“We enter the data of the chassis set-up that was actually used, as well as 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.
“If we then determine that there are deviations between the real obtained circuit data and the existing simulation models for the vehicle or tyres, then we update the specific sub-models of the system accordingly to bring them even closer to reality,” he adds.
Each of these “correlation iterations” lead to further refinements of the simulation and makes the virtual work even more realistic for qualifying and race preparation. “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,” adds Summerscale.
Learning new circuits
Formula E circuits can be completely new to drivers and teams, with some seeing changes year-to-year like the removal of the chicane at Santiago for season six.
Practice is key for Audi’s drivers before every E-Prix. The FIA provides virtual elevation and layout data to all teams, who adapt the data for their own simulators.
“Getting used to tracks within a few laps works very well for me in the simulator,” says di Grassi. “This saves me a lot of valuable time at the real venues on race days, when practice, qualifying and the race take place in quick succession. I can then use this time to further optimise my coordination.”
The trip to Tempelhof Airport, Berlin on the championship’s August 5 return will see six races in nine days on three different layouts. It will be a different prospect altogether. The teams are in the dark, but they will still attempt to simulate every eventuality in the hope they can get a leg up on the opposition.
The series’ organisers are leaving the teams in the dark until the last, pushing the challenge of what will already be one of the toughest race meetings in modern motorsport history up a notch further.
Chassis and tyre strategies
Two other factors of particular importance are the selection of the best possible suspension set-ups and optimising handling of the tyres.
For both of these aspects, Audi can run through all of the permutations in its dynamic driving simulator: springs, dampers, stabilisers and camber. Every component of the suspension set-up is explored intensively.
Accurate tyre simulation is even more important to ensure drivers can maximise their one-shot qualifying effort. Teams seek to exploit maximum grip from the all-weather Michelin rubber over that lap, and in race trim. Achieving peak performance is in the hands of every driver and his engineers.
Using the tyre model integrated into the dynamic driving simulator, working prior to each E-Prix, Audi also examines the influences on vehicle behaviour caused by the various temperatures and pressures that affect the tyres, both internally and externally.
These fluctuate constantly and determine how well the tyres provide grip. If the tyres’ optimal operating window has been exceeded, it isn’t a simple matter of clicking reset in the simulator when the drivers are out on track.
Energy deployment
The test objective with the highest priority on Audi’s preparation programme is energy management. The search for the best possible driving strategy for the race is key – finding the fastest way of utilising the available 52 kWh of energy available over the 45-minute plus one lap race distance, as well as making the most of regen.
In the driving simulator in Neuburg, Audi runs through many different racing scenarios and up to three different motor outputs that are available during the races: 200 kW for normal running, 235 kW in ATTACK MODE and 250 kW via FANBOOST.
Vorsprung through the sim
For Tristan and his team, the simulator is a key tool for adding more trophies to Audi’s cabinet. The Formula E project leader at Audi says: “Every single element of the 2,000-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 tenth of a second in the end.”
Source: https://www.fiaformulae.com/en/news/2020/july/audi-simulator