15/08/2005
NEWS STORY
As a team, we relish the challenge presented by a new circuit. Our engineering preparations begin many months before the race with lap simulations. It takes just 40 seconds to simulate a lap on the computer, but programming the sophisticated models behind this is a lengthier task…
The earlier one can start the process of informing the lap simulation, then the better prepared one is; however, this is not always easy. The starting point for a lap-time simulation is to obtain an accurate circuit map from which the trajectory of the car along the racing line can be described mathematically in three dimensions. Once the circuit configuration has been finalized, detailed maps are issued by the FIA, and work can begin. The boundaries of the tarmac are digitized, and fed into the first stage of the simulation programme, which uses mathematical determines the ideal racing line.
Once this has been established, a car model with an 'average' set-up is introduced. From this, a variety of wing settings and gear ratios can be evaluated to get the basis of the set-up. Once this has been done, refinements are made to weight distribution and suspension settings in order to minimize the virtual lap-time. Subsequently, the team can begin to look at energy requirements from the tyres, to help choose the appropriate compound, and at this stage brake energy requirements, and to some extent brake cooling requirements, can be calculated.
However scientific this may sound, though – as indeed it is – a number of ‘imponderables' can lead to errors in the simulation, that often cannot be corrected until the circuit has been seen and, indeed, until the car has first run on it.
The first of these are the kerbs: where the simulation is only able to assume a driver will use the limits of the tarmac, in reality, they use kerbs wherever they can. If they are relatively smooth and low, they will be used to shortcut what had previously been the ‘ideal' racing line.
Much more problematic, though, is the variation in grip levels: these can differ by up to 15% between the different circuits we race on, according to factors such as the nature of the asphalt and how often the circuit is used. However, to put this into perspective, a 3% variation in grip level on an average circuit can bring a change in lap time of around 1 second and just to make things worse, this parameter varies continually, even during the same day…
Naturally, working 2500 km from the circuit, we can do nothing but assume an average level of grip and work from there until further information is available. How ever, in order to insure against being caught out by any differences in grip relative to our estimations, we conduct numerous simulations at different grip levels in order to have a bank of data at our disposal in the event of changes, so that the appropriate car set-up can be decided upon as quickly as possible.
Once that has pre-race simulation work has been completed, and the car is running, we then begin using a different simulation programme to determine race strategy. In fact, before making our decision on Saturday, over 1,000,000 race scenarios will run through the team's computers!