30-10-2012, 02:03 PM
F1 Track Design and Safety
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INTRODUCTION
Success is all about being in the right place at the right time ….. and the axiom is a guiding principle for designers of motorsport circuits. To avoid problems you need know where and when things are likely to go wrong before cars turn a wheel –and anticipating accidents is a science.
Take barriers, for example, there is little point erecting them in the wrong place –but predicting the right place is a black art. The FIA has developed bespoke software, the Circuit and Safety Analysis System (CSAS), to predict problem areas on F1 circuits.
Where and when cars leave circuits is due to the complex interaction between their design, the driver’s reaction and the specific configuration of the track, and the CSAS allows the input of many variables-lap speeds, engine power curves, car weight changes, aerodynamic characteristics etc –to predict how cars may leave the circuit at particular places. The variables are complex. The impact point of a car continuing in a straight line at a corner is easy to predict, but if the driver has any remaining control and alters the car’s trajectory, or if a mechanical fault introduces fresh variables, its final destination is tricky to model.
TRACK DESIGN
The tracks used in motor sport all are designed to meet certain standards. If a new circuit will ever be used for an international event, its design and layout must be approved by the FIA, before any construction commences. For a permanent circuit, a member of the FIA must inspect it no more than 90 days before a World Championship event, giving adequate time to implement changes.
All design criteria, for curves and straight sections, do not mean the actual track itself, but the actual trajectory followed by the cars whilst racing. Track width on a permanent circuit should be at least 12 metres and should not exceed 15 metres. This avoids bad congestion in corners by limiting the width of the approach to the corner, and having a wide enough track through the corners. There should be 3m minimum clear space along both sides of the track, usually consisting of grass. The maximum length of any new permanent circuit should not exceed 7km to allow drivers to be able to familiarize themselves with all corners on the track. The minimum length of a Formula One circuit will not be less then 3.5km, with the race being no longer than 2h45min. Cross fall across the track for drainage purposes should not exceed 3%, or be less than 1.5%, either from edge to edge or from the centerline to each edge.
The geometry of the track should be designed using the formulae set out by the FIA in Appendix O to the International Sporting Code section 7. These formulae give design criteria for longitudinal profile, visibility, curves, track edges, runoff areas and starting grid specifications. Curves must not get tighter as the turn progresses unless the speed through the corner is less than 125kph, and should preferably have an increasing radius. The maximum number of cars allowed to start in an international race takes all the above geometrical constraints into account, along with the types of cars competing. The number of cars allowed to practice is 20% greater than the number actually allowed to start.
Emergency response.
The emergency response during a motor sport event is one of the most important aspects of safety. When all other safety aspects such as vehicle, and track safety have no more to offer a driver, any further help must come from emergency services. It is vital that drivers can be extracted from damaged vehicles and given the best possible medical care as soon as possible. The 'Recommendations for the supervision of the road and emergency services, Appendix H to the International Sporting code', states the FIA procedures in detail, which will be only covered briefly here.
Any international event should be supervised from a race control centre. This room should be in contact with all marshaling and observation point at all times, and should also have access to emergency services from outside the race such as a helicopter for an evacuation. The Clerk of the Course supervises all emergency procedures from here, after personally ensuring the road is clear of obstacles, is closed to the public and that all observers, marshals and emergency personnel and equipment are in the correct positions.
CIRCUIT AND SAFETY ANALYSIS SYSTEM (CSAS)
Predicting the trajectory and velocity of a racing car when it is driven at the limit within the confines of a racing track, is now the subject of a great deal of analytical work by almost all teams involved in racing at all levels. However, predicting the trajectory and velocity of a car once the driver has lost control of it has not been something the teams have devoted a great deal of time to. This can now also be analyzed though in the same sort of detail, to assess the safety features of the circuits on which it is raced. The two tasks are very different, and the FIA had to start almost from scratch when it set out to develop software for its Circuit and Safety Analysis System (CSAS).
The last two decades have seen a steady build up of the R&D effort going into vehicle dynamics modeling, particularly by those teams that design and develop cars as well as race them. The pace of development has been set by the availability of powerful PC's, the generation of vehicle and component data, and the supply of suitably qualified graduates to carry out the work.
Their task is to be able to model and predict the effects of every nuance of aerodynamic, tire, engine, damper etc., characteristic on the speed of their car at every point on a given circuit. The detail in the model will only be limited by available dynamic characteristics and track data, and will require a driver model to complete the picture. However, they are only interested in the performance of the car while the tires are in contact with the tarmac, and the driver is operating them at or below their peaks.