Features - Technical
MARCH 25, 2001
BY PETER WRIGHT
Now, as from the Spanish GP in April, anything to do with engine and gearbox control is free, and the doors to all other driver aid systems are (hopefully) nailed shut. This apparent about turn by the FIA has happened because of its inevitability, and because it is ultimately in the best interests of the sport. In "exchange" for these concessions, the FIA has gained a commitment by the teams and their motor industry partners to develop certain safety measures relevant to road car safety - an area of prime interest to the FIA and AIT, and the 110 million automobile club members that the joint federations represent.
To make sense of how all this has come about, it is necessary to go back over what has taken place since 1993. The story is that of a high-tech, and highly competitive sport trying to regulate for fast moving technologies while maintaining the sporting element involved. I have stated before that regulations can only be written for that which has been imagined. As the clever people involved in Formula 1 racing think up new concepts, involving technologies for which the vocabulary to describe them must be invented as they are developed, it is impossible to write rules that precisely govern them, ahead of their development. The FIA has had to take the approach of writing "open" regulations that describe the intent, and then only add detailed clauses and clarifications, as they are needed. The process is similar to English Law, where case law determines the judgement in most trials.
Everyone involved has clearly understood that traction control was banned from the 1994 season. Traction control, as understood within the automobile industry as a whole, means: to modulate engine power in response to the speed of the driven wheels compared to the speed of the car, independent of the driver's throttle demand. For it to function, the four wheel speeds must be measured and used to calculate driven wheel slip ratio, and either the throttles (drive-by-wire) or some other engine parameter that can be used to modulate the power output, adjusted until the slip ratio is controlled to the desired value. While there may have been cases of blatant attempts to cheat this by disguising or obliterating the control algorithms, such that they do not show up during software inspection, this is only one of the problems. A more difficult issue to solve has been to determine where "traction control" stops and "driveability" starts. There are numerous ways of making an estimate of wheel spin, other than calculating the actual slip ratio. Comparing engine acceleration to car acceleration, factored by the gear ratio, is a pretty good indicator, and the various RPM's involved can be measured at plenty of locations that are perfectly legal for other purposes. Is a system that smooths engine torque characteristics, such that the engine does not accelerate too quickly in the lower gears, "traction control" or just a way of making the engine more "drivable"? This is just one of many techniques possible. Others could use features such as variable RPM-limits, Pit Lane speed limiters, anti-stall algorithms, and all sorts of complex engine control features to achieve better "driveability".
All these features show up during software inspection, and must be approved by the FIA. The biggest problem has been that some teams seem to believe that others have got away with more "driveability" than they themselves have been allowed. The same issues come up with launch control. During a racing start, the driver must modulate clutch and throttle to achieve the optimum wheel spin for traction in a straight line. A computer is much better at this than a driver, unless he gets it absolutely right by better luck than judgement. What degree of sophisticated clutch and engine control parameter optimization constitutes "launch control"?
Any system that has electronic control (sensors-computer-actuators) can perform control functions that are limited only by the imagination of the control engineers and software writers. Inspection of control code does reveal what is intended in the code that is actually presented. In 2000, evidence was put before the FIA that indicated that there were techniques in existence in Formula 1 that enabled the true function of control code to be masked or destroyed after use, thus evading inspection. The FIA responded by severely limiting the functions of many of the engine control parameters, inhibiting in the process the normal functioning of the engine management system. Mario Illien described the result as trying to fuel the engine via "an extremely expensive carburetor", with all the associated poor throttle response and fuel consumption. It was clearly not a good long-term solution, and not the sort of development that had stimulated Mercedes to become so closely involved with Ilmor and Formula 1. What it did stimulate, was an unaccustomed level of unanimous agreement between the teams.
The Formula 1 Technical Working Group (TWG), made up of all the Technical Directors of the Formula 1 teams, met at the end of last year and put forward a unanimous proposal to free up engine and gearbox electronic control regulations, while more strictly regulating the control of other parts of the car. The rationale was: engines must have electronic controls, and it is desirable that gearboxes have them as they prevent expensive engine over-revs, due to incorrect or premature down-changes. Therefore, in order to eliminate the costly, time consuming, and now shown-to-be-imperfect software inspections, electronics for them should be free. Control system in all other areas - suspension, brakes and steering - would not be permitted. Voila! No more software inspections! No more rumors and accusations!
To bring in regulation changes at such short notice for 2001 required unanimous agreement at all stages of the rule making process. Unfortunately, Ferrari, Prost, Sauber and Minardi (the latter teams all have an involvement with Ferrari) voted against the proposals at the Formula 1 Commission meeting in Monaco in December. They could not therefore be put forward to the World Council for ratification. Why Ferrari went against the proposals, having previously agreed them, is the subject of speculation. Those who believed Ferrari enjoyed a "driveability" advantage last year, continue to believe that it was to provide Ferrari with the same advantage this year. Ferrari claim it was because they were not yet ready with their new engine and needed more time to develop it to race-worthy reliability, without having to develop new control strategies for it. Whatever the reason, the Formula 1 Commission requested the TWG to come back with revised proposals that ensured that no control would be possible in those areas not freed up, and to combine the regulation changes with a development program of enhanced safety, through the application of state-of-the-art control systems relevant to road car safety. If this could be done in time, the new rules would come into force for the Spanish GP on 16th April. This has all happened, and everyone is now busy developing their cars for these new rules.
Engines. All limitations on the use of throttle, ignition, fuel metering, the Pit Lane speed limiter and the engine rev-limiter have been removed. This means that teams can implement traction control in any way they wish, except by the application of the brakes to the driven wheels (a major part of the way road cars operate traction control).
Gearbox. Gear changes can be fully automatic, up and down. Skip shifting is allowed.
Clutch. Operation of the clutch is free. This means, when combined with the new engine rules, that all the driver has to do at the start is to command the car to leave the line. Throttle and clutch will be operated autonomously, to deliver the maximum acceleration. Determining the best settings for this will require calibration of tires and track condition, including an estimate of tire temperature at the start. Wet track conditions would introduce a variable. One might expect to see drivers spinning their wheels from low speeds as they make their way to the grid, and on the warm-up lap, to calibrate the conditions for last second setting up of the system.
A feature that is expressly forbidden is one that detects the start lights, and automatically commands the car to start when the red lights go out, thus eliminating the delay due to the driver's reaction time.
Differentials. Differential control is free, provided it does not permit the transfer of torque from a slower to a faster wheel. This is what a torque-steer differential is able to accomplish.
Brakes. No powered devices are allowed. This neatly bans ABS and variable brake balance. By banning power addition, the hardware can be inspected for an actuator with a power supply leading to it (wires, or pneumatic or hydraulic hoses).
Steering. Power steering will be permitted in 2001, and banned thereafter. It was too late to expect teams to take power steering systems off mid-season, as steering geometries have evolved with it, e.g. castor angles are higher. Most teams now have either an electro-hydraulic or an electric power steering system fitted, and eliminating them form next year is going to make the driver's job harder. Driver's have got used to them and enjoy the ease of controlling the steering in fast, high-download corners. One can expect to see renewed concentration during training on the development of upper-body, shoulder and arm muscles!
Suspension. The active suspension ban has been effective in stopping the variation in aerodynamic attitude possible with a powered system. However, a number of teams were developing, and may have been running, various forms of active dampers. These were permitted, provided the control system only closed the loop around the damper's response, not the car's response. The favorite approach is to use magneto-rheological fluid in the damper, and such systems are available in some forms of racing in the US. The special damper fluid's viscosity is altered, very quickly, by subjecting it to a variable magnetic field. A similar, but less practical system has been used, achieving the same effect by subjecting the fluid to an electro-static field (electro-rheological damper) but it requires Kilovolts. These systems are now specifically banned.
The FIA intends to continue to monitor software, but now with the emphasis on system integrity instead of on policing. It will however be able to keep an eye on trends - in case someone thinks up something not yet imagined.
The safety systems the teams have agreed to develop in exchange for the above concessions are:
Driver start abort. At the moment, if a driver has a problem just before the start, he holds up his hand, and the marshal opposite him waves a yellow flag to signal to the starter, who aborts the start. In the past, this process has not always worked, and the stricken driver has to duck down into his cockpit and cross his fingers, while all the cars behind him try and avoid his car in the smoke and excitement of the start. From 2002, drivers will be equipped with a system, which they can initiate to send a signal electronically to the starting sequence controller, which will automatically abort the start. This should eliminate the steps in the process that require one human to see clearly the hand or flag signal waved by another human. It must be better and safer.
Collision warning. Those who remember Michael Schumacher running into the back of David Coulthard's McLaren, in the rain at Spa in 1998, will appreciate just how dangerous it must be to be driving in the blinding spray of a car ahead. There have been many similar accidents over the years and some great drivers have suffered as a result. It is intended that for 2003, a system will be in place that warns drivers that there is a slower car ahead. This is unlikely to use forward-looking radar (as is being developed for adaptive cruise control on road cars, but which is still some way off as a collision avoidance system) but is more likely to be based on the system that identifies the position of all the cars on the circuit and informs Race Control. This system is based on transponders in the car that communicate, bi-directionally, with wires buried across the track every few hundred meters, and is operated by Formula One Communications as part of their digital TV and information enterprise.
Speed limits. The same system is capable of communicating a driver warning that a speed restriction has been applied to all or part of the track. The former equates to a yellow flag, and will come into force in 2002; the latter has the potential of replacing the Safety Car, and will be applied from 2003. Initially the drivers will just be warned of the local speed limit, and have to keep to it, being subject to heavy penalties for contravention. Just as when a Pit Lane speed limit was applied, and it took only a few races (and some useful income for the FIA from the fines) for the drivers to demand an automatic speed limiting device to be fitted to their cars, they will no doubt demand technical assistance to protect their pockets and their points.
Rear-view mirrors. For 2002, rear-view mirrors will be increased in width by 30mm, from 120x50mm to 150x50mm.
It is the variable and flexibly applied speed limits system, preferably with automatic control of the car's speed, that the FIA is most interested in. The technology already exists for road cars and has been demonstrated in several European countries. The problems of introducing such a system into road cars, and on all relevant roads, is one of public acceptance and the political will to mandate it. The potential for making speed limits more relevant to the conditions and the time of day, on any particular section of road, be it urban streets around schools or to cater for different weather conditions on a motorway, is pretty obvious, and the returns in terms of safety, less infringement of the law and less frustrated drivers are enormous. Formula 1 can contribute to the debate as to when these devices will become politically acceptable, and help convince the public that they are not wimpish devices, but a sensible and practical approach to saving lives.
Will these regulation changes cause a big leap forward in lap speeds and a shake up of the established order, when they are introduced in Spain in April? I do not think so. Full traction control and automatic gear-changes were pretty mature technologies when they were banned at the end of 1993. Most teams and their engine partners, even though the combinations have been shuffled somewhat, were around then, and had developed systems. It is unlikely that there is a great advantage to be gained by any new development. For sure, McLaren-Mercedes' and Ferrari's systems will work very well, and they will probably have done the most testing and fine tuning. In the dry, the performance advantage overall will not be very noticeable, especially with the big increase in tire grip already evident, due to the Bridgestone-Michelin tire war. In the wet, the rain-maestros, such as Schumacher and Barrichello, will have less of an advantage, which is a pity. The re-introduction of launch controls should make all starts perfect, with only the driver's reaction time to differentiate them. That will remove one wild card that often stirs up the grid order, if it comes about as described. The loss of any opportunity to apply powered controls to steering, suspension and brakes should make hardly any difference at all, as the new rules only tighten up the existing ones. The biggest difference of all will be in the size of the driver's biceps!