Page 65 - ATZ WORLDWIDE

electrical energy and the power level for
the boost in each sector of the track. 3 projectors,
120 Hz WUXGA,
However, the entire amount of energy 215° field of view,
that can be released for each lap is lim- screen height: 2.4 m,
ited; in Mexico it was limited to 3.92 MJ. radius: 4 m Cockpit of Porsche 919 Hybrid,
ECUs as HiL,
The additional power of 300 kW could digital audio and intercom
therefore be applied for a duration of
13.07 s per lap. With a lap time of roughly
1:26 min, this corresponds to 15.2 % of
the lap. It is always the goal of strategic
energy distribution to minimise the lap
time. However, since the powerful tempo-
rary all-wheel drive also influences han-
dling, the influence on driving dynamics
must also be considered.
The development of the boost strategy Motion platform: 1 operator workstation,
for a new track begins with the optimisa- - VI-grade DiM 4 engineer workstations,
tion of the energy distribution using the (Driver in Motion) same working process as
- 9 degrees of freedom
on the race track
vehicle model. The necessary prerequi-
sites for these lap time evaluations on FIGURE 4 Profile of the Porsche LMP1 Team driving simulator with 3 projectors, cockpit, motion platform
the track typically involve high-quality and 5 workplaces (© Porsche)
measurement data that can be used to
derive the vehicle trajectory. 01:40
As an alternative, a driving line can be
recorded with a factory driver on the driv- Lap times from 6 h of Mexico Collective Test,
sorted in ascending order,
ing simulator, FIGURE 4, due to the highly 2 vehicles per manufacturer
precise track models. This driving line is 01:38
then used as a basis for the first simula-
tions to prepare for the race and therefore
also to optimise the boost strategy. A first 01:36
iteration variant of the boost strategy is
available as the result of the optimisation.
It is then used as a starting point for 01:34
another session in the driving simulator.
The goal of the session is to fine-tune the Lap time [mm:ss]
boost strategy in terms of vehicle balance 01:32
and driving quality. This is done on the
basis of a subjective evaluation by one or
more factory drivers in the simulator. Fur- 01:30
thermore, variants are developed that, for Competitor 1
example, include a strategy for the start of Competitor 2
the race or different strategies to provide 01:28 Porsche
assistance with a passing manoeuvre. As
the original variant is used as a basis for
comparison, all variants generated on the 01:26
driving simulator are evaluated once more 0 5 10 15 20 25 30
during an offline simulation. At the end of Total number of laps driven per vehicle [-]
the process, relative lap time differences FIGURE 5 Lap times from the “6 h of Mexico” 2016 Collective Test (© Porsche)
compared to the original variant without
any driver influence are available.
The result of this race preparation pro-
cess is a high-quality base strategy. The tool, it has a positive side effect on new The results show that, thanks to the
time available during free practice can tracks in particular as the drivers are procedure described above, the lap times
be used effectively to fine-tune the familiar with the track layout and have by the Porsche vehicle were already more
remaining unknown variables. This may already driven the vehicle virtually on consistent and faster during the first free
include the response to weather condi- the new track. The FIGURE 5 illustrates practice than those of the competitors.
tions, the interaction between tyres and the lap times from the flying laps by the Porsche ends its LMP1 engagement with
asphalt or the response to traffic condi- three LMP1 manufacturers in the first the 2017 season, but will also use the
tions. Although the driving simulator is session of the “6 h of Mexico” race (col- simulator technology in future motor-
not typically used as a driver training lective test) in ascending order. sport projects.
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